ORCID Profile
0000-0003-0429-3579
Current Organisations
University of the Aegean
,
University of Western Australia
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Research Topics
In Research Link Australia (RLA), "Research Topics" refer to ANZSRC FOR and SEO codes. These topics are either sourced from ANZSRC FOR and SEO codes listed in researchers' related grants or generated by a large language model (LLM) based on their publications.
Top 5 Research Topics
ANZSRC Field of Research (FoR)
Astronomical and Space Sciences | Cosmology and Extragalactic Astronomy | Astronomical and Space Instrumentation | Galactic Astronomy | Photonics, Optoelectronics and Optical Communications
ANZSRC Socio-Economic Objective (SEO)
Expanding Knowledge in the Physical Sciences | Expanding Knowledge in Technology | Expanding Knowledge in Engineering | Expanding Knowledge in the Information and Computing Sciences |
Related Links
Publications
Which haloes host Herschel-ATLAS galaxies in the local Universe?
Publisher: Oxford University Press (OUP)
Date: 16-02-2011
Acupressure and Acupuncture Use in the Peripartum Period
Publisher: Ovid Technologies (Wolters Kluwer Health)
Date: 08-07-2021
Galaxy And Mass Assembly (GAMA): refining the local galaxy merger rate using morphological information
Publisher: Oxford University Press (OUP)
Date: 07-10-2014
Herschel-ATLAS: multi-wavelength SEDs and physical properties of 250 μm selected galaxies atz< 0.5
Publisher: Oxford University Press (OUP)
Date: 02-11-2021
An empirical measurement of the halo mass function from the combination of GAMA DR4, SDSS DR12, and REFLEX II data
Publisher: Oxford University Press (OUP)
Date: 06-04-2022
Abstract: We construct the halo mass function (HMF) from the GAMA (Galaxy And Mass Assembly) galaxy group catalogue over the mass range of 1012.7–1015.5 M⊙, and find good agreement with the expectation from Lambda cold dark matter. In comparison to previous studies, this result extends the mass range over which the HMF has now been measured over by an order of magnitude. We combine the GAMA data release (DR) 4 HMF with similar data from the Sloan Digital Sky Survey (SDSS) DR12 and REFLEX II (ROSAT-ESO Flux Limited X-ray Galaxy Cluster Survey) surveys, and fit a four-parameter Murray–Robotham–Power function, valid at $\\tilde{z} \\approx 0.1$, yielding a density normalization of log10 (ϕ* Mpc$^{3})= -3.96^{+0.55}_{-0.82}$, a high mass turnover of log10 (M* M$_{\\odot }^{-1})=14.13^{+0.43}_{-0.40}$, a low-mass power-law slope of $\\alpha =-1.68^{+0.21}_{-0.24}$, and a high-mass softening parameter of $\\beta =0.63^{+0.25}_{-0.11}$. If we fold in the constraint on ΩM from the Planck 2018 cosmology, we are able to reduce these uncertainties further, but this relies on the assumption that the power-law trend can be extrapolated from 1012.7 M⊙ to zero mass. Throughout, we highlight the effort needed to improve on our HMF measurement: improved halo mass estimates that do not rely on calibration to simulations reduced halo mass uncertainties needed to mitigate the strong Eddington bias that arises from the steepness of the HMF low-mass slope and deeper wider area spectroscopic surveys. To our halo mass limit of 1012.7 M⊙, we are directly resolving (‘seeing’) 41 ± 5 per cent of the total mass density, i.e. ΩM,& .7 = 0.128 ± 0.016, opening the door for the direct construction of three-dimensional dark matter mass maps at Mpc resolution.
Dependence of GAMA galaxy halo masses on the cosmic web environment from 100 deg2of KiDS weak lensing data
Publisher: Oxford University Press (OUP)
Date: 20-07-2016
JWST PEARLS. Prime Extragalactic Areas for Reionization and Lensing Science: Project Overview and First Results
Publisher: American Astronomical Society
Date: 14-12-2022
Abstract: We give an overview and describe the rationale, methods, and first results from NIRCam images of the JWST “Prime Extragalactic Areas for Reionization and Lensing Science” (PEARLS) project. PEARLS uses up to eight NIRCam filters to survey several prime extragalactic survey areas: two fields at the North Ecliptic Pole (NEP) seven gravitationally lensing clusters two high redshift protoclusters and the iconic backlit VV 191 galaxy system to map its dust attenuation. PEARLS also includes NIRISS spectra for one of the NEP fields and NIRSpec spectra of two high-redshift quasars. The main goal of PEARLS is to study the epoch of galaxy assembly, active galactic nucleus (AGN) growth, and First Light. Five fields—the JWST NEP Time-Domain Field (TDF), IRAC Dark Field, and three lensing clusters—will be observed in up to four epochs over a year. The cadence and sensitivity of the imaging data are ideally suited to find faint variable objects such as weak AGN, high-redshift supernovae, and cluster caustic transits. Both NEP fields have sightlines through our Galaxy, providing significant numbers of very faint brown dwarfs whose proper motions can be studied. Observations from the first spoke in the NEP TDF are public. This paper presents our first PEARLS observations, their NIRCam data reduction and analysis, our first object catalogs, the 0.9–4.5 μ m galaxy counts and Integrated Galaxy Light. We assess the JWST sky brightness in 13 NIRCam filters, yielding our first constraints to diffuse light at 0.9–4.5 μ m. PEARLS is designed to be of lasting benefit to the community.
Galaxy And Mass Assembly (GAMA): Defining passive galaxy samples and searching for the UV upturn
Publisher: Oxford University Press (OUP)
Date: 19-12-2019
Abstract: We use data from the GAMA and GALEX surveys to demonstrate that the UV upturn, an unexpected excess of ultraviolet flux from a hot stellar component, seen in the spectra of many early-type galaxies, arises from processes internal to in idual galaxies with no measurable influence from the galaxies’ larger environment. We first define a clean s le of passive galaxies without a significant contribution to their UV flux from low-level star formation. We confirm that galaxies with the optical colours of red sequence galaxies often have signs of residual star formation, which, without other information, would prevent a convincing demonstration of the presence of UV upturns. However, by including (NUV−u) and WISE (W2–W3) colours, and FUV data where it exists, we can convincingly constrain s les to be composed of non-star-forming objects. Using such a s le, we examine GALEX photometry of low-redshift GAMA galaxies in a range of low-density environments, from groups to the general field, searching for UV upturns. We find a wide range of (NUV−r) colours, entirely consistent with the range seen – and attributed to the UV upturn – in low-redshift red sequence cluster galaxies. The range of colours is independent of group multiplicity or velocity dispersion, with isolated passive galaxies just as likely to have blue UV-to-optical colours, implying significant upturn components, as those in richer groups and in the previous data on clusters. This is supported by equivalent results for (FUV−r) colours which are clear indicators of upturn components.
Detection, Size, Measurement, and Structural Analysis Limits for the 2MASS, UKIDSS-LAS, and VISTA VIKING Surveys
Publisher: Cambridge University Press (CUP)
Date: 2014
DOI: 10.1017/PASA.2013.41
Abstract: The 2MASS, UKIDSS-LAS, and VISTA VIKING surveys have all now observed the GAMA 9hr region in the K s band. Here we compare the detection rates, photometry, basic size measurements, and single-component GALFIT structural measurements for a s le of 37 591 galaxies. We explore the sensitivity limits where the data agree for a variety of issues including: detection, star–galaxy separation, photometric measurements, size and ellipticity measurements, and Sérsic measurements. We find that 2MASS fails to detect at least 20% of the galaxy population within all magnitude bins, however for those that are detected we find photometry is robust (± 0.2 mag) to 14.7 AB mag and star–galaxy separation to 14.8 AB mag. For UKIDSS-LAS we find incompleteness starts to enter at a flux limit of 18.9 AB mag, star–galaxy separation is robust to 16.3 AB mag, and structural measurements are robust to 17.7 AB mag. VISTA VIKING data are complete to approximately 20.0 AB mag and structural measurements appear robust to 18.8 AB mag.
The XXL Survey
Publisher: EDP Sciences
Date: 20-11-2018
DOI: 10.1051/0004-6361/201732507
Abstract: Context. Superclusters form from the largest enhancements in the primordial density perturbation field and extend for tens of Mpc, tracing the large-scale structure of the Universe. X-ray detections and systematic characterisations of superclusters and the properties of their galaxies have only been possible in the last few years. Aims. We characterise XLSSsC N01, a rich supercluster at z ~ 0.3 detected in the XXL Survey, composed of X-ray clusters of different virial masses and X-ray luminosities. As one of the first studies on this topic, we investigate the stellar populations of galaxies in different environments in the supercluster region. Methods. We study a magnitude-limited ( r ≤ 20) and a mass-limited s le (log( M * ∕ M ⊙ ) ≥ 10.8) of galaxies in the virialised region and in the outskirts of 11 XLSSsC N01 clusters, in high-density field regions, and in the low-density field. We compute the stellar population properties of galaxies using spectral energy distribution (SED) and spectral fitting techniques, and study the dependence of star formation rates (SFR), colours, and stellar ages on environment. Results. For r ≤ 20, the fraction of star-forming/blue galaxies, computed either from the specific-SFR (sSFR) or rest-frame colour, shows depletion within the cluster virial radii, where the number of galaxies with log (sSFR/ yr −1 ) −12 and with ( g − r ) restframe 0.6 is lower than in the field. For log( M * ∕ M ⊙ ) ≥ 10.8, no trends with environment emerge, as massive galaxies are mostly already passive in all environments. No differences among low- and high-density field members and cluster members emerge in the sSFR-mass relation in the mass-complete regime. Finally, the luminosity-weighted age–mass relation of the passive populations within cluster virial radii show signatures of recent environmental quenching. Conclusions. The study of luminous and massive galaxies in this supercluster shows that while environment has a prominent role in determining the fractions of star-forming/blue galaxies, its effects on the star formation activity in star-forming galaxies are negligible.
Two-phase galaxy evolution: the cosmic star formation histories of spheroids and discs
Publisher: Oxford University Press (OUP)
Date: 03-2013
DOI: 10.1093/MNRAS/STS717
Deep Extragalactic VIsible Legacy Survey (DEVILS): identification of AGN through SED fitting and the evolution of the bolometric AGN luminosity function
Publisher: Oxford University Press (OUP)
Date: 14-12-2021
Abstract: Active galactic nuclei (AGN) are typically identified through radio, mid-infrared, or X-ray emission or through the presence of broad and/or narrow emission lines. AGN can also leave an imprint on a galaxy’s spectral energy distribution (SED) through the re-processing of photons by the dusty torus. Using the SED fitting code ProSpect with an incorporated AGN component, we fit the far-ultraviolet to far-infrared SEDs of ∼494 000 galaxies in the D10-COSMOS field and ∼230 000 galaxies from the GAMA survey. By combining an AGN component with a flexible star formation and metallicity implementation, we obtain estimates for the AGN luminosities, stellar masses, star formation histories, and metallicity histories for each of our galaxies. We find that ProSpect can identify AGN components in 91 per cent of galaxies pre-selected as containing AGN through narrow-emission line ratios and the presence of broad lines. Our ProSpect-derived AGN luminosities show close agreement with luminosities derived for X-ray selected AGN using both the X-ray flux and previous SED fitting results. We show that incorporating the flexibility of an AGN component when fitting the SEDs of galaxies with no AGN has no significant impact on the derived galaxy properties. However, in order to obtain accurate estimates of the stellar properties of AGN host galaxies, it is crucial to include an AGN component in the SED fitting process. We use our derived AGN luminosities to map the evolution of the AGN luminosity function for 0 & z & 2 and find good agreement with previous measurements and predictions from theoretical models.
Galaxy and Mass Assembly (GAMA): fine filaments of galaxies detected within voids
Publisher: Oxford University Press (OUP)
Date: 04-03-2014
The environment and characteristics of low-redshift galaxies detected by the Herschel-ATLAS
Publisher: Oxford University Press (OUP)
Date: 24-10-2011
Galaxy And Mass Assembly (GAMA): Structural Investigation of Galaxies via Model Analysis
Publisher: Oxford University Press (OUP)
Date: 03-2012
Herschel★-ATLAS: rapid evolution of dust in galaxies over the last 5 billion years
Publisher: Oxford University Press (OUP)
Date: 06-09-2011
Galaxy And Mass Assembly (GAMA): bulge-disc decomposition of KiDS data in the nearby Universe
Publisher: Oxford University Press (OUP)
Date: 18-08-2022
Abstract: We derive single Sérsic fits and bulge-disc decompositions for 13 096 galaxies at redshifts z & 0.08 in the GAMA II equatorial survey regions in the Kilo-Degree Survey (KiDS) g, r, and i bands. The surface brightness fitting is performed using the Bayesian two-dimensional profile fitting code ProFit. We fit three models to each galaxy in each band independently with a fully automated Markov chain Monte Carlo analysis: a single Sérsic model, a Sérsic plus exponential and a point source plus exponential. After fitting the galaxies, we perform model selection and flag galaxies for which none of our models are appropriate (mainly mergers/Irregular galaxies). The fit quality is assessed by visual inspections, comparison to previous works, comparison of independent fits of galaxies in the overlap regions between KiDS tiles and bespoke simulations. The latter two are also used for a detailed investigation of systematic error sources. We find that our fit results are robust across various galaxy types and image qualities with minimal biases. Errors given by the MCMC underestimate the true errors typically by factors 2–3. Automated model selection criteria are accurate to $\\gt 90{{\\ \\rm per\\ cent}}$ as calibrated by visual inspection of a subs le of galaxies. We also present g−r component colours and the corresponding colour–magnitude diagram, consistent with previous works despite our increased fit flexibility. Such reliable structural parameters for the components of a erse s le of galaxies across multiple bands will be integral to various studies of galaxy properties and evolution. All results are integrated into the GAMA database.
The SAMI Galaxy Survey: instrument specification and target selection
Publisher: Oxford University Press (OUP)
Date: 13-01-2015
SKYSURF-4: Panchromatic Hubble Space Telescope All-Sky Surface-brightness Measurement Methods and Results
Publisher: American Astronomical Society
Date: 11-05-2023
Abstract: The diffuse, unresolved sky provides most of the photons that the Hubble Space Telescope (HST) receives, yet remains poorly understood. The HST Archival Legacy program SKYSURF aims to measure the 0.2–1.6 μ m sky surface brightness (sky-SB) from over 140,000 HST images. We describe a sky-SB measurement algorithm designed for SKYSURF that is able to recover the input sky-SB from simulated images to within 1% uncertainty. We present our sky-SB measurements estimated using this algorithm on the entire SKYSURF database. Comparing our sky-SB spectral energy distribution (SED) to measurements from the literature shows general agreements. Our SKYSURF SED also reveals a possible dependence on the Sun angle, indicating either nonisotropic scattering of solar photons off interplanetary dust or an additional component to zodiacal light. Finally, we update the diffuse light limits in the near-IR based on the methods from Carleton et al., with values of 0.009 MJy sr −1 (22 nW m −2 sr −1 ) at 1.25 μ m, 0.015 MJy sr −1 (32 nW m −2 sr −1 ) at 1.4 μ m, and 0.013 MJy sr −1 (25 nW m −2 sr −1 ) at 1.6 μ m. These estimates provide the most stringent all-sky constraints to date in this wavelength range. SKYSURF sky-SB measurements are made public on the official SKYSURF website and will be used to constrain diffuse light in future papers.
The XXL Survey
Publisher: EDP Sciences
Date: 07-2022
DOI: 10.1051/0004-6361/202142057
Abstract: Why are some galaxy groups pervaded by a hot X-ray emitting intracluster medium, whilst others have no detectable X-ray emission? Is the presence of hot gas a reliable indicator of dynamical maturity, and can some virialised groups contain little or none of it? What are the main differences between s les of groups selected in the X-ray and optical bands? We address these questions by studying 232 optical spectroscopically selected groups from the Galaxy And Mass Assembly (GAMA) survey that overlap the XXL X-ray cluster survey. X-ray aperture flux measurements combined with GAMA group data provides the largest available s le of optical groups with detailed galaxy membership information and consistently measured X-ray fluxes and upper limits. A s le of 142 of these groups is ided into three subsets based on the relative strength of X-ray and optical emission, and we see a trend in galaxy properties between these subsets: X-ray overluminous groups contain a lower fraction of both blue and star forming galaxies compared with X-ray underluminous systems. X-ray overluminous groups also have a more dominant central galaxy, with a magnitude gap between first and second ranked galaxies on average 0.22 mag larger than in underluminous groups. Moreover, the central galaxy in overluminous groups lies closer to the luminosity-weighted centre of the group. We examine a number of other structural properties of our groups, such as axis ratio, velocity dispersion, and group crossing time, and find evidence of trends with X-ray emission in some of these properties despite the high stochastic noise arising from the limited number of group galaxies. We attribute the trends we see primarily to the evolutionary state of groups, with X-ray overluminous systems being more dynamically evolved than underluminous groups. The X-ray overluminous groups have had more time to develop a luminous intragroup medium, quench member galaxies, and build the mass of the central galaxy through mergers compared to underluminous groups. However, an interesting minority of X-ray underluminous groups have properties that suggest them to be dynamically mature. We find that the lack of hot gas in these systems cannot be accounted for by high star formation efficiency, suggesting that high gas entropy resulting from feedback is the likely cause of their weak X-ray emission.
Galaxy And Mass Assembly (GAMA): extended intragroup light in a group at z = 0.2 from deep Hyper Suprime-Cam images
Publisher: Oxford University Press (OUP)
Date: 24-11-2022
Abstract: We present a pilot study to assess the potential of Hyper Suprime-Cam Public Data Release 2 (HSC-PDR2) images for the analysis of extended faint structures within groups of galaxies. We examine the intragroup light (IGL) of the group 400138 (Mdyn = 1.3 ± 0.5 × 1013 M⊙, z ∼ 0.2) from the Galaxy And Mass Assembly (GAMA) survey using Hyper Suprime-Cam Subaru Strategic Program Public Data Release 2 (HSC-SSP PDR2) images in g, r, and i bands. We present the most extended IGL measurement to date, reaching down to $\\mu _{g}^{\\rm {lim}}=30.76$ mag arcsec−2 (3σ 10 × 10 arcsec2) at a semimajor axis of 275 kpc. The IGL shows mean colour values of g − i = 0.92, g − r = 0.60, and r − i = 0.32 (±0.01). The IGL stellar populations are younger (2–2.5 Gyr) and less metal rich ([Fe/H] ∼ −0.4) than those of the host group galaxies. We find a range of IGL fractions as a function of total group luminosity of ${\\sim} 2\\!-\\!36 {{\\ \\rm per\\ cent}}$ depending on the definition of IGL, with larger fractions the bluer the observation wavelength. The early-type to late-type galaxy ratio suggests that 400138 is a more evolved group, dominated by early-type galaxies, and the IGL fraction agrees with that of other similarly evolved groups. These results are consistent with tidal stripping of the outer parts of Milky Way-like galaxies as the main driver of the IGL build-up. This is supported by the detection of substructure in the IGL towards the galaxy member 1660615 suggesting a recent interaction (& Gyr ago) of that galaxy with the core of the group.
Galaxy And Mass Assembly (GAMA): Data Release 4 and the z < 0.1 total and z < 0.08 morphological galaxy stellar mass functions
Publisher: Oxford University Press (OUP)
Date: 02-03-2022
Abstract: In Galaxy And Mass Assembly Data Release 4 (GAMA DR4), we make available our full spectroscopic redshift s le. This includes 248 682 galaxy spectra, and, in combination with earlier surveys, results in 330 542 redshifts across five sky regions covering ∼250 deg2. The redshift density, is the highest available over such a sustained area, has exceptionally high completeness (95 per cent to rKiDS = 19.65 mag), and is well-suited for the study of galaxy mergers, galaxy groups, and the low redshift (z & 0.25) galaxy population. DR4 includes 32 value-added tables or Data Management Units (DMUs) that provide a number of measured and derived data products including GALEX, ESO KiDS, ESO VIKING, WISE, and HerschelSpace Observatory imaging. Within this release, we provide visual morphologies for 15 330 galaxies to z & 0.08, photometric redshift estimates for all 18 million objects to rKiDS ∼ 25 mag, and stellar velocity dispersions for 111 830 galaxies. We conclude by deriving the total galaxy stellar mass function (GSMF) and its sub- ision by morphological class (elliptical, compact-bulge and disc, diffuse-bulge and disc, and disc only). This extends our previous measurement of the total GSMF down to 106.75 M$_{\\odot } \\, h_{70}^{-2}$ and we find a total stellar mass density of ρ* = (2.97 ± 0.04) × 108 M$_{\\odot } \\, h_{70}$ Mpc−3 or $\\Omega _*=(2.17 \\pm 0.03) \\times 10^{-3} \\, h_{70}^{-1}$. We conclude that at z & 0.1, the Universe has converted 4.9 ± 0.1 per cent of the baryonic mass implied by big bang Nucleosynthesis into stars that are gravitationally bound within the galaxy population.
Galaxy And Mass Assembly (GAMA): curation and reanalysis of 16.6k redshifts in the G10/COSMOS region
Publisher: Oxford University Press (OUP)
Date: 19-12-2015
Eddington's demon: inferring galaxy mass functions and other distributions from uncertain data
Publisher: Oxford University Press (OUP)
Date: 06-12-2018
Galaxy And Mass Assembly (GAMA): assimilation of KiDS into the GAMA database
Publisher: Oxford University Press (OUP)
Date: 03-06-2020
Abstract: The Galaxy And Mass Assembly Survey (GAMA) covers five fields with highly complete spectroscopic coverage (& per cent) to intermediate depths (r & 19.8 or i & 19.0 mag), and collectively spans 250 deg2 of equatorial or southern sky. Four of the GAMA fields (G09, G12, G15, and G23) reside in the European Southern Observatory (ESO) VST KiDS and ESO VISTA VIKING survey footprints, which combined with our GALEX, WISE, and Herschel data provide deep uniform imaging in the $FUV/NUV/u/g/r/i/Z/Y/J/H/K_s/W1/W2/W3/W4/P100/P160/S250/S350/S500$ bands. Following the release of KiDS DR4, we describe the process by which we ingest the KiDS data into GAMA (replacing the SDSS data previously used for G09, G12, and G15), and redefine our core optical and near-infrared (NIR) catalogues to provide a complete and homogeneous data set. The source extraction and analysis is based on the new ProFound image analysis package, providing matched-segment photometry across all bands. The data are classified into stars, galaxies, artefacts, and ambiguous objects, and objects are linked to the GAMA spectroscopic target catalogue. Additionally, a new technique is employed utilizing ProFound to extract photometry in the unresolved MIR–FIR regime. The catalogues including the full FUV–FIR photometry are described and will be fully available as part of GAMA DR4. They are intended for both standalone science, selection for targeted follow-up with 4MOST, as well as an accompaniment to the upcoming and ongoing radio arrays now studying the GAMA 23h field.
Erratum
Publisher: Oxford University Press (OUP)
Date: 27-11-2021
Galaxy And Mass Assembly (GAMA): the input catalogue and star-galaxy separation
Publisher: Oxford University Press (OUP)
Date: 02-2010
Galaxy And Mass Assembly: the G02 field, Herschel–ATLAS target selection and data release 3
Publisher: Oxford University Press (OUP)
Date: 24-11-2017
Herschel★-ATLAS/GAMA: dusty early-type galaxies and passive spirals
Publisher: Oxford University Press (OUP)
Date: 12-2011
SKYSURF: Constraints on Zodiacal Light and Extragalactic Background Light through Panchromatic HST All-sky Surface-brightness Measurements. I. Survey Overview and Methods
Publisher: American Astronomical Society
Date: 15-09-2022
Abstract: We give an overview and describe the rationale, methods, and testing of the Hubble Space Telescope (HST) Archival Legacy project “SKYSURF.” SKYSURF uses HST’s unique capability as an absolute photometer to measure the ∼0.2–1.7 μ m sky-surface brightness (sky-SB) from 249,861 WFPC2, ACS, and WFC3 exposures in ∼1400 independent HST fields. SKYSURF’s panchromatic data set is designed to constrain the discrete and diffuse UV to near-IR sky components: Zodiacal Light (ZL), Kuiper Belt Objects (KBOs), Diffuse Galactic Light (DGL), and the discrete plus diffuse Extragalactic Background Light (EBL). We outline SKYSURF’s methods to: (1) measure sky-SB levels between detected objects (2) measure the discrete EBL, most of which comes from AB≃17–22 mag galaxies and (3) estimate how much truly diffuse light may exist. Simulations of HST WFC3/IR images with known sky values and gradients, realistic cosmic ray (CR) distributions, and star plus galaxy counts were processed with nine different algorithms to measure the “Lowest Estimated Sky-SB” (LES) in each image between the discrete objects. The best algorithms recover the LES values within 0.2% when there are no image gradients, and within 0.2%–0.4% when there are 5%–10% gradients. We provide a proof of concept of our methods from the WFC3/IR F125W images, where any residual diffuse light that HST sees in excess of zodiacal model predictions does not depend on the total object flux that each image contains. This enables us to present our first SKYSURF results on diffuse light in Carleton et al.
ProSpect: generating spectral energy distributions with complex star formation and metallicity histories
Publisher: Oxford University Press (OUP)
Date: 26-04-2020
Abstract: We introduce ProSpect, a generative galaxy spectral energy distribution (SED) package that encapsulates the best practices for SED methodologies in a number of astrophysical domains. ProSpect comes with two popular families of stellar population libraries (BC03 and EMILES), and a large variety of methods to construct star formation and metallicity histories. It models dust through the use of a Charlot & Fall attenuation model, with re-emission using Dale far-infrared templates. It also has the ability to model active galactic nucleus (AGN) through the inclusion of a simple AGN and hot torus model. Finally, it makes use of MAPPINGS-III photoionization tables to produce line emission features. We test the generative and inversion utility of ProSpect through application to the Shark galaxy formation semi-analytic code, and informed by these results produce fits to the final ultraviolet to far-infrared photometric catalogues produces by the Galaxy and Mass Assembly Survey. As part of the testing of ProSpect, we also produce a range of simple photometric stellar mass approximations covering a range of filters for both observed frame and rest-frame photometry.
Galaxy And Mass Assembly (GAMA): colour- and luminosity-dependent clustering from calibrated photometric redshifts
Publisher: Oxford University Press (OUP)
Date: 03-08-2012
Galaxy and Mass Assembly (GAMA): ugriz galaxy luminosity functions
Publisher: Oxford University Press (OUP)
Date: 12-12-2011
Galaxy and Mass Assembly (GAMA): merging galaxies and their properties
Publisher: Oxford University Press (OUP)
Date: 10-09-2014
PKS 2250–351: A giant radio galaxy in Abell 3936
Publisher: Cambridge University Press (CUP)
Date: 2020
DOI: 10.1017/PASA.2019.49
Abstract: We present a detailed analysis of the radio galaxy PKS $2250{-}351$ , a giant of 1.2 Mpc projected size, its host galaxy, and its environment. We use radio data from the Murchison Widefield Array, the upgraded Giant Metre-wavelength Radio Telescope, the Australian Square Kilometre Array Pathfinder, and the Australia Telescope Compact Array to model the jet power and age. Optical and IR data come from the Galaxy And Mass Assembly (GAMA) survey and provide information on the host galaxy and environment. GAMA spectroscopy confirms that PKS $2250{-}351$ lies at $z=0.2115$ in the irregular, and likely unrelaxed, cluster Abell 3936. We find its host is a massive, ‘red and dead’ elliptical galaxy with negligible star formation but with a highly obscured active galactic nucleus dominating the mid-IR emission. Assuming it lies on the local M – $\\sigma$ relation, it has an Eddington accretion rate of $\\lambda_{\\rm EDD}\\sim 0.014$ . We find that the lobe-derived jet power (a time-averaged measure) is an order of magnitude greater than the hotspot-derived jet power (an instantaneous measure). We propose that over the lifetime of the observed radio emission ( ${\\sim} 300\\,$ Myr), the accretion has switched from an inefficient advection-dominated mode to a thin disc efficient mode, consistent with the decrease in jet power. We also suggest that the asymmetric radio morphology is due to its environment, with the host of PKS $2250{-}351$ lying to the west of the densest concentration of galaxies in Abell 3936.
Using velocity dispersion to estimate halo mass: Is the Local Group in tension with ΛCDM?
Publisher: Oxford University Press (OUP)
Date: 06-03-2018
DOI: 10.1093/MNRAS/STY590
Non-parametric cell-based photometric proxies for galaxy morphology: methodology and application to the morphologically defined star formation–stellar mass relation of spiral galaxies in the local uni
Publisher: Oxford University Press (OUP)
Date: 12-2013
MUSE spectroscopy and deep observations of a unique compact JWST target, lensing cluster CLIO
Publisher: Oxford University Press (OUP)
Date: 04-01-2018
Quantifying cosmic variance
Publisher: Oxford University Press (OUP)
Date: 02-09-2010
Galaxy And Mass Assembly (GAMA): Gas Fueling of Spiral Galaxies in the Local Universe. I. The Effect of the Group Environment on Star Formation in Spiral Galaxies
Publisher: American Astronomical Society
Date: 14-02-2017
Herschel-ATLAS: the far-infrared-radio correlation at z < 0.5★
Publisher: Oxford University Press (OUP)
Date: 29-10-2010
The Wide Area VISTA Extra-Galactic Survey (WAVES)
Publisher: Springer International Publishing
Date: 2016
Environmental dependence of SFRs in late-type GAMA galaxies
Publisher: Cambridge University Press (CUP)
Date: 09-2011
DOI: 10.1017/S1743921312009404
Abstract: Present and past gas-fuelling of galaxies is expected to depend upon both the properties of the galaxies themselves, as well as their larger-scale environments. In the case of galaxies in groups the environment, i.e the group mass, can be probed by measuring the velocity dispersion of the group members, as done with the GAMA Galaxy Group catalogue (Robotham et al . 2011), probing the halo mass function all the way to small groups. The gas-fuelling rate of normal late-type galaxies can be traced by the SFR under the assumption of a steady state between gas-fuelling and gas-consumption by SF. We present a method to estimate disk opacities from UV/optical photometric characteristics, calibrated using the radiative transfer model of Popescu et al . (2011), applied to UV-Opt-FIR GAMA/H-ATLAS photometry for a subset of GAMA galaxies. We use the method to extract attenuation corrected SFRs for a large s le of late-type GAMA galaxies, which we use in an initial application to constrain the dependency of star formation/gas-fuelling in late-type galaxies on mass of parent DMH, and compactness of galaxy group.
Deep Extragalactic VIsible Legacy Survey (DEVILS): consistent multiwavelength photometry for the DEVILS regions (COSMOS, XMMLSS, and ECDFS)
Publisher: Oxford University Press (OUP)
Date: 05-06-2021
Abstract: The Deep Extragalactic VIsible Legacy Survey (DEVILS) is an ongoing high-completeness, deep spectroscopic survey of ∼60 000 galaxies to Y & 21.2 mag, over ∼6 deg2 in three well-studied deep extragalactic fields: D10 (COSMOS), D02 (XMMLSS), and D03 (ECDFS). Numerous DEVILS projects all require consistent, uniformly derived and state-of-the-art photometric data with which to measure galaxy properties. Existing photometric catalogues in these regions either use varied photometric measurement techniques for different facilities/wavelengths leading to inconsistencies, older imaging data and/or rely on source detection and photometry techniques with known problems. Here, we use the ProFound image analysis package and state-of-the-art imaging data sets (including Subaru-HSC, VST-VOICE, VISTA-VIDEO, and UltraVISTA-DR4) to derive matched-source photometry in 22 bands from the FUV to 500 $\\mu$m. This photometry is found to be consistent, or better, in colour analysis to previous approaches using fixed-size apertures (which are specifically tuned to derive colours), but produces superior total source photometry, essential for the derivation of stellar masses, star formation rates, star formation histories, etc. Our photometric catalogue is described in detail and, after internal DEVILS team projects, will be publicly released for use by the broader scientific community.
Jeans that fit
Publisher: Oxford University Press (OUP)
Date: 15-01-2018
DOI: 10.1093/MNRAS/STY118
Herschel-ATLAS: counterparts from the ultraviolet-near-infrared in the science demonstration phase catalogue★
Publisher: Oxford University Press (OUP)
Date: 11-08-2011
The Shapes of Galaxy Groups: Footballs or Frisbees?
Publisher: American Astronomical Society
Date: 10-01-2008
DOI: 10.1086/523885
Galaxy and Mass Assembly: FUV, NUV, ugrizYJHK Petrosian, Kron and Sérsic photometry
Publisher: Oxford University Press (OUP)
Date: 12-2010
Herschel-ATLAS/GAMA: spatial clustering of low-redshift submm galaxies
Publisher: Oxford University Press (OUP)
Date: 22-10-2012
PEARLS: Low Stellar Density Galaxies in the El Gordo Cluster Observed with JWST
Publisher: American Astronomical Society
Date: 08-2023
Abstract: A full understanding of how unusually large ultradiffuse galaxies (UDGs) fit into our conventional theory of galaxy formation remains elusive, despite the large number of objects identified locally. A natural extension of UDG research is the study of similar galaxies at higher redshift to establish how their properties may evolve over time. However, this has been a challenging task given how severely systematic effects and cosmological surface brightness dimming inhibit our ability to analyze low surface brightness galaxies at high z . Here, we present a s le of low stellar surface density galaxies (LDGs) at moderate redshift, likely the progenitors of local UDGs, identified using deep near-IR observations of the El Gordo cluster at z = 0.87 with JWST. By stacking eight NIRCAM filters, we reach an apparent surface brightness sensitivity of 24.59 mag arcsec −2 , which is faint enough to be complete to the bright end of the LDG population. Our analysis identifies significant differences between this population and UDGs observed locally, such as their color and size distributions, which suggest that the UDG progenitors at high z are bluer and more extended than UDGs at z = 0. This suggests that multiple mechanisms are responsible for the UDG formation and that prolonged transformation of cluster dwarfs is not a primary UDG formation mechanism at high z . Furthermore, we find a slight overabundance of LDGs in El Gordo, and, in contrast to findings in local clusters, our analysis does not show a deficit of LDGs in the center of El Gordo, implying that tidal destruction of LDGs is significant between z = 0.87 and z = 0.
GAMA/G10-COSMOS/3D-HST: the 0 < z < 5 cosmic star formation history, stellar-mass, and dust-mass densities
Publisher: Oxford University Press (OUP)
Date: 11-12-2017
Deep extragalactic visible legacy survey (DEVILS): the emergence of bulges and decline of disc growth since z = 1
Publisher: Oxford University Press (OUP)
Date: 30-04-2022
Abstract: We present a complete structural analysis of the ellipticals (E), diffuse bulges (dB), compact bulges (cB), and discs (D) within a redshift range 0 & z & 1, and stellar mass log10(M*/M⊙) ≥ 9.5 volume-limited s le drawn from the combined DEVILS and HST-COSMOS region. We use the profit code to profile over ∼35 000 galaxies for which visual classification into single or double component was pre-defined in Paper-I. Over this redshift range, we see a growth in the total stellar mass density (SMD) of a factor of 1.5. At all epochs we find that the dominant structure, contributing to the total SMD, is the disc, and holds a fairly constant share of $\\sim 60{{\\ \\rm per\\ cent}}$ of the total SMD from z = 0.8 to z = 0.2, dropping to $\\sim 30{{\\ \\rm per\\ cent}}$ at z = 0.0 (representing $\\sim 33{{\\ \\rm per\\ cent}}$ decline in the total disc SMD). Other classes (E, dB, and cB) show steady growth in their numbers and integrated stellar mass densities. By number, the most dramatic change across the full mass range is in the growth of diffuse bulges. In terms of total SMD, the biggest gain is an increase in massive elliptical systems, rising from 20 per cent at z = 0.8 to equal that of discs at z = 0.0 (30 per cent) representing an absolute mass growth of a factor of 2.5. Overall, we see a clear picture of the emergence and growth of all three classes of spheroids over the past 8 Gyr, and infer that in the later half of the Universe’s timeline spheroid-forming processes and pathways (secular evolution, mass-accretion, and mergers) appear to dominate mass transformation over quiescent disc growth.
Modelling the cosmic spectral energy distribution and extragalactic background light over all time
Publisher: Oxford University Press (OUP)
Date: 06-11-2017
Herschel-ATLAS: Dust temperature and redshift distribution of SPIRE and PACS detected sources using submillimetre colours
Publisher: EDP Sciences
Date: 07-2010
The SAMI Galaxy Survey: Data Release One with emission-line physics value-added products
Publisher: Oxford University Press (OUP)
Date: 11-12-2017
The SAMI Galaxy Survey: global stellar populations on the size–mass plane
Publisher: Oxford University Press (OUP)
Date: 24-08-2017
Radio source extraction with ProFound
Publisher: Oxford University Press (OUP)
Date: 05-06-2019
Exploring galaxy formation and evolution via structural decomposition
Publisher: AIP
Date: 2010
DOI: 10.1063/1.3458501
The JWST PEARLS View of the El Gordo Galaxy Cluster and of the Structure It Magnifies
Publisher: American Astronomical Society
Date: 07-2023
Abstract: The massive galaxy cluster El Gordo ( z = 0.87) imprints multitudes of gravitationally lensed arcs onto James Webb Space Telescope Near-Infrared Camera (NIRCam) images. Eight bands of NIRCam imaging were obtained in the “Prime Extragalactic Areas for Reionization and Lensing Science” (“PEARLS”) program. Point-spread function–matched photometry across Hubble Space Telescope and NIRCam filters supplies new photometric redshifts. A new light-traces-mass lens model based on 56 image multiplicities identifies the two mass peaks and yields a mass estimate within 500 kpc of (7.0 ± 0.30) × 10 14 M ⊙ . A search for substructure in the 140 cluster members with spectroscopic redshifts confirms the two main mass components. The southeastern mass peak that contains the brightest cluster galaxy is more tightly bound than the northwestern one. The virial mass within 1.7 Mpc is (5.1 ± 0.60)×10 14 M ⊙ , lower than the lensing mass. A significant transverse velocity component could mean the virial mass is underestimated. We contribute one new member to the previously known z = 4.32 galaxy group. Intrinsic (delensed) positions of the five secure group members span a physical extent of ∼60 kpc. 13 additional candidates selected by spectroscopic hotometric constraints are small and faint, with a mean intrinsic luminosity ∼2.2 mag fainter than L * . NIRCam imaging admits a fairly wide range of brightnesses and morphologies for the group members, suggesting a more erse galaxy population in this galaxy overdensity.
Galaxy And Mass Assembly (GAMA): the connection between metals, specific SFR and H i gas in galaxies: the Z–SSFR relation
Publisher: Oxford University Press (OUP)
Date: 11-05-2013
Galaxy And Mass Assembly: search for a population of high-entropy galaxy groups
Publisher: Oxford University Press (OUP)
Date: 06-05-2017
Galaxy And Mass Assembly (GAMA): the effect of close interactions on star formation in galaxies
Publisher: Oxford University Press (OUP)
Date: 08-07-2015
Galaxy And Mass Assembly (GAMA): growing up in a bad neighbourhood – how do low-mass galaxies become passive?
Publisher: Oxford University Press (OUP)
Date: 03-12-2015
The Subaru HSC weak lensing mass-observable scaling relations of spectroscopic galaxy groups from the GAMA survey
Publisher: Oxford University Press (OUP)
Date: 08-01-2022
Abstract: We utilize the galaxy shape catalogue from the first-year data release of the Subaru Hyper Suprime-Cam (HSC) survey to study the dark matter content of galaxy groups in the Universe using weak lensing. We use galaxy groups from the Galaxy Mass and Assembly galaxy survey in approximately 100 sq. degrees of the sky that overlap with the HSC survey as lenses. We restrict our analysis to the 1587 groups with at least five members. We ide these groups into six bins each of group luminosity and group member velocity dispersion and measure the lensing signal with a signal-to-noise ratio of 55 and 51 for these two different selections, respectively. We use a Bayesian halo model framework to infer the halo mass distribution of our groups binned in the two different observable properties and constrain the power-law scaling relation and the scatter between mean halo masses and the two-group observable properties. We obtain a 5 per cent constraint on the litude of the scaling relation between halo mass and group luminosity with 〈M〉 = (0.81 ± 0.04) × 1014 h−1 M⊙ for Lgrp = 1011.5 h−2 L⊙, and a power-law index of α = 1.01 ± 0.07. We constrain the litude of the scaling relation between halo mass and velocity dispersion to be 〈M〉 = (0.93 ± 0.05) × 1014 h−1 M⊙ for $\\sigma = 500\\, {\\rm km\\, s}^{-1}$ and a power-law index to be α = 1.52 ± 0.10. However, these scaling relations are sensitive to the exact cuts applied to the number of group members. Comparisons with similar scaling relations from the literature show that our results are consistent and have significantly reduced errors.
Soft Tactile Sensors for Rehabilitation Robotic Hand with 3D Printed Folds
Publisher: Springer Singapore
Date: 07-12-2017
Galaxy and mass assembly (GAMA): dust obscuration in galaxies and their recent star formation histories
Publisher: Oxford University Press (OUP)
Date: 08-11-2010
Deep Extragalactic VIsible Legacy Survey (DEVILS): motivation,design, and target catalogue
Publisher: Oxford University Press (OUP)
Date: 14-06-2018
The stellar-to-halo mass relation of GAMA galaxies from 100 deg2of KiDS weak lensing data
Publisher: Oxford University Press (OUP)
Date: 12-04-2016
DOI: 10.1093/MNRAS/STW747
Galaxy And Mass Assembly (GAMA): the bright void galaxy population in the optical and mid-IR
Publisher: Oxford University Press (OUP)
Date: 09-09-2015
The eROSITA Final Equatorial Depth Survey (eFEDS)
Publisher: EDP Sciences
Date: 10-2022
DOI: 10.1051/0004-6361/202243101
Abstract: Aims. The circumgalactic medium (CGM) plays an important role in galaxy evolution as the main interface between the star-forming body of galaxies and the surrounding cosmic network of in- and out-flowing matter. In this work, we aim to characterize the hot phase of the CGM in a large s le of galaxies using recent soft-X-ray observations made by SRG /eROSITA. Methods. We stack X-ray events from the ‘eROSITA Final Equatorial Depth Survey’ (eFEDS) around central galaxies in the 9hr field of the ‘GAlaxy and Mass Assembly’ (GAMA) survey to construct radially projected X-ray luminosity profiles in the 0.5–2 keV rest frame energy band as a function of their stellar mass and specific star formation rate. We consider s les of quiescent (star-forming) galaxies in the stellar mass range 2 × 10 10 –10 12 M ⊙ (3 × 10 9 –6 × 10 11 M ⊙ ). Results. For quiescent galaxies, the X-ray profiles are clearly extended throughout the available mass range however, the measured profile is likely biased high because of projection effects, as these galaxies tend to live in dense and hot environments. For the most massive star-forming s les (≥10 11 M ⊙ ), there is a hint of detection of extended emission. On the other hand, for star-forming galaxies with 10 11 M ⊙ the X-ray stacked profiles are compatible with unresolved sources and are consistent with the expected emission from faint active galactic nuclei (AGN) and X-ray binaries. We measure for the first time the mean relation between average X-ray luminosity and stellar mass separately for quiescent and star-forming galaxies. We find that the relation is different for the two galaxy populations: high-mass (≥10 11 M ⊙ ) star-forming or quiescent galaxies follow the expected scaling of virialized hot haloes, while lower mass star-forming galaxies show a less prominent luminosity and a weaker dependence on stellar mass consistent with empirical models of the population of weak AGN. When comparing our results with state-of-the-art numerical simulations (IllustrisTNG and EAGLE), we find overall consistency on the average emission on large ( 80 kpc) scales at masses ≥10 11 M ⊙ , but disagreement on the small scales, where brighter-than-observed compact cores are predicted. The simulations also do not predict the clear differentiation that we observe between quiescent and star-forming galaxies in our s les. Conclusions. This is a stepping stone towards a more profound understanding of the hot phase of the CGM, which holds a key role in the regulation of star formation. Future analysis using eROSITA all-sky survey data, combined with future generation galaxy evolution surveys, shall provide much enhanced quantitative measurements and mapping of the CGM and its hot phase(s).
Galaxy And Mass Assembly (GAMA): Environmental Quenching of Centrals and Satellites in Groups
Publisher: Oxford University Press (OUP)
Date: 09-01-2019
xGASS
Publisher: Oxford University Press (OUP)
Date: 07-10-2019
Abstract: We present a structural decomposition analysis of the galaxies in the extended GALEX Arecibo SDSS Survey (xGASS) using (gri) images from the Sloan Digital Sky Survey. Utilizing the 2D Bayesian light profile fitting code ProFit, we fit single- and double-component models taking advantage of a robust Markov chain Monte Carlo optimization algorithm in which we assume a Sérsic profile for single-component models and a combination of a Sérsic bulge and near-exponential disc (0.5 ≤ n ≤ 1.5) for double-component models. We investigate the effect of bulges on the atomic hydrogen (H i) content in galaxies by revisiting the H i-to-stellar mass scaling relations with the bulge-to-total ratio measured in the ProFit decompositions. We show that, at both fixed total and disc stellar mass, more bulge-dominated galaxies have systematically lower H i masses, implying that bulge-dominated galaxies with large H i reservoirs are rare in the local Universe. We see similar trends when separating galaxies by a bulge-to-total ratio based either on luminosity or stellar mass, however, the trends are more evident with luminosity. Importantly, when controlling for both stellar mass and star formation rate, the separation of atomic gas content reduces to within 0.3 dex between galaxies of different bulge-to-total ratios. Our findings suggest that the presence of a photometric bulge has little effect on the global H i gas reservoirs of local galaxies.
K-CLASH: spatially resolving star-forming galaxies in field and cluster environments at z ≈ 0.2–0.6
Publisher: Oxford University Press (OUP)
Date: 22-05-2020
Abstract: We present the KMOS-CLASH (K-CLASH) survey, a K-band Multi-Object Spectrograph (KMOS) survey, of the spatially resolved gas properties and kinematics of 191 (pre-dominantly blue) H α-detected galaxies at 0.2 ≲ z ≲ 0.6 in field and cluster environments. K-CLASH targets galaxies in four Cluster Lensing And Supernova survey with Hubble (CLASH) fields in the KMOS IZ-band, over 7 arcmin radius (≈2–3 Mpc) fields of view. K-CLASH aims to study the transition of star-forming galaxies from turbulent, highly star-forming disc-like and peculiar systems at z ≈ 1–3, to the comparatively quiescent, ordered late-type galaxies at z ≈ 0, and to examine the role of clusters in the build-up of the red sequence since z ≈ 1. In this paper, we describe the K-CLASH survey, present the s le, and provide an overview of the K-CLASH galaxy properties. We demonstrate that our s le comprises star-forming galaxies typical of their stellar masses and epochs, residing both in field and cluster environments. We conclude K-CLASH provides an ideal s le to bridge the gap between existing large integral-field spectroscopy surveys at higher and lower redshifts. We find that star-forming K-CLASH cluster galaxies at intermediate redshifts have systematically lower stellar masses than their star-forming counterparts in the field, hinting at possible ‘downsizing’ scenarios of galaxy growth in clusters at these epochs. We measure no difference between the star formation rates of H α-detected, star-forming galaxies in either environment after accounting for stellar mass, suggesting that cluster quenching occurs very rapidly during the epochs probed by K-CLASH, or that star-forming K-CLASH galaxies in clusters have only recently arrived there, with insufficient time elapsed for quenching to have occurred.
From the far-ultraviolet to the far-infrared – galaxy emission at 0 ≤ z ≤ 10 in the shark semi-analytic model
Publisher: Oxford University Press (OUP)
Date: 02-09-2019
Abstract: We combine the shark semi-analytic model of galaxy formation with the prospect software tool for spectral energy distribution (SED) generation to study the multiwavelength emission of galaxies from the far-ultraviolet (FUV) to the far-infrared (FIR) at 0 ≤ z ≤ 10. We produce a physical model for the attenuation of galaxies across cosmic time by combining a local Universe empirical relation to compute the dust mass of galaxies from their gas metallicity and mass, attenuation curves derived from radiative transfer calculations of galaxies in the eagle hydrodynamic simulation suite, and the properties of shark galaxies. We are able to produce a wide range of galaxies, from the z = 8 star-forming galaxies with almost no extinction, z = 2 submillimetre galaxies, down to the normal star-forming and red-sequence galaxies at z = 0. Quantitatively, we find that shark reproduces the observed (i) z = 0 FUV-to-FIR, (ii) 0 ≤ z ≤ 3 rest-frame K-band, and (iii) 0 ≤ z ≤ 10 rest-frame FUV luminosity functions, (iv) z ≤ 8 UV slopes, (v) the FUV-to-FIR number counts (including the widely disputed 850 μm), (vi) redshift distribution of bright $850\\, \\mu$m galaxies, and (vii) the integrated cosmic SED from z = 0 to 1 to an unprecedented level. This is achieved without the need to invoke changes in the stellar initial mass function, dust-to-metal mass ratio, or metal enrichment time-scales. Our model predicts star formation in galaxy discs to dominate in the FUV-to-optical, while bulges dominate at the NIR at all redshifts. The FIR sees a strong evolution in which discs dominate at z ≤ 1 and starbursts (triggered by both galaxy mergers and disc instabilities, in an even mix) dominate at higher redshifts, even out to z = 10.
Galaxy And Mass Assembly (GAMA): a deeper view of the mass, metallicity and SFR relationships
Publisher: Oxford University Press (OUP)
Date: 09-07-2013
4MOST Consortium Survey 7: Wide-Area VISTA Extragalactic Survey (WAVES)
Publisher: European Southern Observatory (ESO)
Date: 2019
Galaxy And Mass Assembly (GAMA): a forensic SED reconstruction of the cosmic star formation history and metallicity evolution by galaxy type
Publisher: Oxford University Press (OUP)
Date: 11-09-2020
Abstract: We apply the spectral energy distribution (SED) fitting code ProSpect to multiwavelength imaging for ∼7000 galaxies from the GAMA survey at z & 0.06, in order to extract their star formation histories. We combine a parametric description of the star formation history with a closed-box evolution of metallicity where the present-day gas-phase metallicity of the galaxy is a free parameter. We show with this approach that we are able to recover the observationally determined cosmic star formation history (CSFH), an indication that stars are being formed in the correct epoch of the Universe, on average, for the manner in which we are conducting SED fitting. We also show the contribution to the CSFH of galaxies of different present-day visual morphologies and stellar masses. Our analysis suggests that half of the mass in present-day elliptical galaxies was in place 11 Gyr ago. In other morphological types, the stellar mass formed later, up to 6 Gyr ago for present-day irregular galaxies. Similarly, the most massive galaxies in our s le were shown to have formed half their stellar mass by 11 Gyr ago, whereas the least massive galaxies reached this stage as late as 4 Gyr ago (the well-known effect of ‘galaxy downsizing’). Finally, our metallicity approach allows us to follow the average evolution in gas-phase metallicity for populations of galaxies and extract the evolution of the cosmic metal mass density in stars and in gas, producing results in broad agreement with independent, higher redshift observations of metal densities in the Universe.
Physical properties and evolution of (sub-)millimetre-selected galaxies in the galaxy formation simulation shark
Publisher: Oxford University Press (OUP)
Date: 21-09-2020
Abstract: We thoroughly explore the properties of (sub)-millimetre (mm) selected galaxies (SMGs) in the shark semi-analytic model of galaxy formation. Compared to observations, the predicted number counts at wavelengths (λ) 0.6–2 mm and redshift distributions at 0.1–2 mm, agree well. At the bright end (≳1 mJy), shark galaxies are a mix of mergers and disc instabilities. These galaxies display a stacked far-ultraviolet (FUV)-to-far-infrared (FIR) spectrum that agrees well with observations. We predict that current optical/NIR surveys are deep enough to detect bright (& mJy) λ = 0.85–2 mm-selected galaxies at z ≲ 5, but too shallow to detect counterparts at higher redshift. A James Webb Space Telescope 10 000s survey should detect all counterparts for galaxies with S0.85mm ≳ 0.01 mJy. We predict SMG’s disks contribute significantly (negligibly) to the rest-frame UV (IR). We investigate the 0 ≤ z ≤ 6 evolution of the intrinsic properties of & mJy λ = 0.85–2 mm-selected galaxies finding their: (i) stellar masses are $\\gt 10^{10.2}\\rm \\, M_{\\odot }$, with the 2 mm ones tracing the most massive galaxies ($\\gt 10^{11}\\rm \\, M_{\\odot }$) (ii) specific star formation rates (SFR) are mildly (≈3–10 times) above the main sequence (MS) (iii) host halo masses are $\\gtrsim 10^{12.3}\\, \\rm M_{\\odot }$, with 2 mm galaxies tracing the most massive haloes (protoclusters) (iv) SMGs have lower dust masses ($\\approx 10^{8}\\, \\rm M_{\\odot }$), higher dust temperatures (≈40–45 K) and higher rest-frame V-band attenuation (& .5) than MS galaxies (v) sizes decrease with redshift, from 4 kpc at z = 1 to ≲1 kpc at z = 4 and (vi) the carbon monoxide line spectra of S0.85mm ≳ 1 mJy sources peak at 4 → 3. Finally, we study the contribution of SMGs to the molecular gas and cosmic SFR density at 0 ≤ z ≤ 10, finding that & mJy sources make a negligible contribution at z ≳ 3 and 5, respectively, suggesting current observations have unveiled the majority of the SF at 0 ≤ z ≤ 10.
The X-ray invisible Universe. A look into the halos undetected by eROSITA
Publisher: Oxford University Press (OUP)
Date: 25-10-2023
Galaxy and Mass Assembly (GAMA): The stellar mass budget by galaxy type
Publisher: Oxford University Press (OUP)
Date: 02-2016
A Short Research Note on Calculating Exact Distribution Functions and Random Sampling for the 3D NFW Profile
Publisher: American Astronomical Society
Date: 18-06-2018
Galaxy And Mass Assembly: accurate panchromatic photometry from optical priors using lambdar
Publisher: Oxford University Press (OUP)
Date: 12-04-2016
DOI: 10.1093/MNRAS/STW832
H-ATLAS/GAMA: the nature and characteristics of optically red galaxies detected at submillimetre wavelengths
Publisher: Oxford University Press (OUP)
Date: 30-12-2015
JWST's PEARLS: Bright 1.5–2.0 μm Dropouts in the Spitzer/IRAC Dark Field
Publisher: American Astronomical Society
Date: 28-12-2022
Abstract: Using the first epoch of four-band NIRCam observations obtained by the James Webb Space Telescope (JWST) Prime Extragalactic Areas for Reionization and Lensing Science Program in the Spitzer IRAC Dark Field, we search for F150W and F200W dropouts. In 14.2 arcmin 2 , we have found eight F150W dropouts and eight F200W dropouts, all brighter than 27.5 mag (the brightest being ∼24 mag) in the band to the red side of the break. As they are detected in multiple bands, these must be real objects. Their nature, however, is unclear, and characterizing their properties is important for realizing the full potential of JWST. If the observed color decrements are due to the Lyman break, these objects should be at z ≳ 11.7 and z ≳ 15.4, respectively. The color diagnostics show that at least four F150W dropouts are far away from the usual contaminators encountered in dropout searches (red galaxies at much lower redshifts or brown dwarf stars). While the diagnostics of the F200W dropouts are less certain due to the limited number of passbands, at least one of them is likely not a known type of contaminant, and the rest are consistent with either high-redshift galaxies with evolved stellar populations or old galaxies at z ≈ 3–8. If a significant fraction of our dropouts are indeed at z ≳ 12, we have to face the severe problem of explaining their high luminosities and number densities. Spectroscopic identifications of such objects are urgently needed.
Galaxy And Mass Assembly (GAMA): $\mathcal {M_\star }\text{--}R_{\rm e}$ relations ofz= 0 bulges, discs and spheroids
Publisher: Oxford University Press (OUP)
Date: 06-07-2016
Galaxy And Mass Assembly (GAMA): the 0.013 < z < 0.1 cosmic spectral energy distribution from 0.1 m to 1 mm
Publisher: Oxford University Press (OUP)
Date: 21-12-2012
WALLABY – an SKA Pathfinder H i survey
Publisher: Springer Science and Business Media LLC
Date: 07-2020
Tracing the cosmic web
Publisher: Oxford University Press (OUP)
Date: 03-08-2017
JWST’s PEARLS: Dust Attenuation and Gravitational Lensing in the Backlit-galaxy System VV 191
Publisher: American Astronomical Society
Date: 20-03-2023
Abstract: We derive the spatial and wavelength behavior of dust attenuation in the multiple-armed spiral galaxy VV 191b using backlighting by the superimposed elliptical system VV 191a in a pair with an exceptionally favorable geometry for this measurement. Imaging using the James Webb Space Telescope and Hubble Space Telescope spans the wavelength range 0.3–4.5 μ m with high angular resolution, tracing the dust in detail from 0.6–1.5 μ m. Distinct dust lanes continue well beyond the bright spiral arms, and trace a complex web, with a very sharp radial cutoff near 1.7 Petrosian radii. We present attenuation profiles and coverage statistics in each band at radii 14–21 kpc. We derive the attenuation law with wavelength the data both within and between the dust lanes clearly favor a stronger reddening behavior ( R = A V / E B − V ≈ 2.0 between 0.6 and 0.9 μ m, approaching unity by 1.5 μ m) than found for starbursts and star-forming regions of galaxies. Power-law extinction behavior ∝ λ − β gives β = 2.1 from 0.6–0.9 μ m. R decreases at increasing wavelengths ( R ≈ 1.1 between 0.9 and 1.5 μ m), while β steepens to 2.5. Mixing regions of different column density flattens the wavelength behavior, so these results suggest a different grain population than in our vicinity. The NIRCam images reveal a lens arc and counterimage from a background galaxy at z ≈ 1, spanning 90° azimuthally at 2.″8 from the foreground elliptical-galaxy nucleus, and an additional weakly lensed galaxy. The lens model and imaging data give a mass/light ratio M / L B = 7.6 in solar units within the Einstein radius 2.0 kpc.
4MOST: Project overview and information for the First Call for Proposals
Publisher: European Southern Observatory (ESO)
Date: 2019
Galaxy And Mass Assembly (GAMA): the environments of high- and low-excitation radio galaxies
Publisher: Oxford University Press (OUP)
Date: 15-05-2017
Galaxy And Mass Assembly (GAMA): stellar mass functions by Hubble type
Publisher: Oxford University Press (OUP)
Date: 29-08-2014
Galaxy tagging: photometric redshift refinement and group richness enhancement
Publisher: Oxford University Press (OUP)
Date: 18-06-2018
Herschel-ATLAS: VISTA VIKING near-infrared counterparts in the Phase 1 GAMA 9-h data★
Publisher: Oxford University Press (OUP)
Date: 10-05-2012
H-ATLAS/GAMA: quantifying the morphological evolution of the galaxy population using cosmic calorimetry
Publisher: Oxford University Press (OUP)
Date: 20-08-2015
SimSpin v2.6.0 - Constructing synthetic spectral IFU cubes for comparison with observational surveys
Publisher: Cambridge University Press (CUP)
Date: 2023
DOI: 10.1017/PASA.2023.47
Spectroscopy of the supernova H0pe host galaxy at redshift 1.78
Publisher: EDP Sciences
Date: 07-2023
DOI: 10.1051/0004-6361/202346964
Abstract: Supernova (SN) H0pe was discovered as a new transient in James Webb Space Telescope (JWST) NIRCam images of the galaxy cluster PLCK G165.7+67.0 taken as part of the Prime Extragalactic Areas for Reionization and Lensing Science (PEARLS) JWST GTO program (ID 1176) on 2023 March 30. The transient is a compact source associated with a background galaxy that is stretched and triply imaged by the strong gravitational lensing of the cluster. This paper reports spectra in the 950–1370 nm observer frame of two of the galaxy images obtained with Large Binocular Telescope (LBT) Utility Camera in the Infrared (LUCI) in long-slit mode two weeks after the JWST observations. The in idual and average spectra show the [O II ] λλ 3727,3730 doublet and the Balmer and 4000 Å breaks at redshift z = 1.783 ± 0.002. The code investigating galaxy emission (CIGALE) best-fit model of the spectral energy distribution indicates that the host galaxy of SN H0pe is massive ( M star ≃ 6 × 10 10 M ⊙ after correcting for a magnification factor μ ∼ 7) with a predominantly intermediate-age (∼2 Gyr) stellar population, moderate extinction, and a magnification-corrected star formation rate ≃13 M ⊙ yr −1 , consistent with being below the main sequence of star formation. These properties suggest that H0pe might be a type Ia SN. Additional observations of SN H0pe and its host recently carried out with JWST (JWST-DD-4446 PI: B. Frye) will be able to both determine the SN classification and confirm its association with the galaxy analyzed in this work.
Galaxy luminosities in 2dF percolation-inferred galaxy (2PIGG) groups
Publisher: American Astronomical Society
Date: 12-2006
DOI: 10.1086/508130
Galaxy and mass assembly: luminosity and stellar mass functions in GAMA groups
Publisher: Oxford University Press (OUP)
Date: 21-09-2020
Abstract: How do galaxy properties (such as stellar mass, luminosity, star formation rate, and morphology) and their evolution depend on the mass of their host dark matter halo? Using the Galaxy and Mass Assembly group catalogue, we address this question by exploring the dependence on host halo mass of the luminosity function (LF) and stellar mass function (SMF) for grouped galaxies sub ided by colour, morphology, and central/satellite. We find that spheroidal galaxies in particular dominate the bright and massive ends of the LF and SMF, respectively. More massive haloes host more massive and more luminous central galaxies. The satellites LF and SMF, respectively, show a systematic brightening of characteristic magnitude, and increase in characteristic mass, with increasing halo mass. In contrast to some previous results, the faint-end and low-mass slopes show little systematic dependence on halo mass. Semi-analytic models and simulations show similar or enhanced dependence of central mass and luminosity on halo mass. Faint and low-mass simulated satellite galaxies are remarkably independent of halo mass, but the most massive satellites are more common in more massive groups. In the first investigation of low-redshift LF and SMF evolution in group environments, we find that the red/blue ratio of galaxies in groups has increased since redshift z ≈ 0.3 relative to the field population. This observation strongly suggests that quenching of star formation in galaxies as they are accreted into galaxy groups is a significant and ongoing process.
Galaxy And Mass Assembly (GAMA): stellar mass growth of spiral galaxies in the cosmic web
Publisher: Oxford University Press (OUP)
Date: 16-02-2016
DOI: 10.1093/MNRAS/STW134
GAMA/H-ATLAS: a meta-analysis of SFR indicators – comprehensive measures of the SFR–M*relation and cosmic star formation history atz < 0.4
Publisher: Oxford University Press (OUP)
Date: 07-06-2016
Galaxy And Mass Assembly (GAMA): the galaxy stellar mass function at z < 0.06
Publisher: Oxford University Press (OUP)
Date: 02-2012
GAMA + KiDS: empirical correlations between halo mass and other galaxy properties near the knee of the stellar-to-halo mass relation
Publisher: Oxford University Press (OUP)
Date: 09-2020
Abstract: We use KiDS weak lensing data to measure variations in mean halo mass as a function of several key galaxy properties (namely stellar colour, specific star formation rate, Sérsic index, and effective radius) for a volume-limited s le of GAMA galaxies in a narrow stellar mass range [M* ∼ (2–5) × 1010 M⊙]. This mass range is particularly interesting, inasmuch as it is where bimodalities in galaxy properties are most pronounced, and near to the break in both the galaxy stellar mass function and the stellar-to-halo mass relation (SHMR). In this narrow mass range, we find that both size and Sérsic index are better predictors of halo mass than either colour or SSFR, with the data showing a slight preference for Sérsic index. In other words, we find that mean halo mass is more tightly correlated with galaxy structure than either past star formation history or current star formation rate. Our results lead to an approximate lower bound on the dispersion in halo masses among log M* ≈ 10.5 galaxies: We find that the dispersion is ≳0.3 dex. This would imply either that offsets from the mean SHMR are closely coupled to size/structure or that the dispersion in the SHMR is larger than what past results have suggested. Our results thus provide new empirical constraints on the relationship between stellar and halo mass assembly at this particularly interesting mass range.
Galaxy And Mass Assembly (GAMA): the galaxy stellar mass function to z = 0.1 from the r-band selected equatorial regions
Publisher: Oxford University Press (OUP)
Date: 11-05-2017
Observing merger trees in a new light
Publisher: Cambridge University Press (CUP)
Date: 2018
DOI: 10.1017/PASA.2018.34
Abstract: Merger trees harvested from cosmological N -body simulations encode the assembly histories of dark matter halos over cosmic time and are a fundamental component of semi-analytical models of galaxy formation. The ability to compare the tools used to construct merger trees, namely halo finders and tree building algorithms, in an unbiased and systematic manner is critical to assess the quality of merger trees. In this paper, we present the dendrogram, a novel method to visualise merger trees, which provides a comprehensive characterisation of a halo’s assembly history—tracking subhalo orbits, halo merger events, and the general evolution of halo properties. We show the usefulness of the dendrogram as a diagnostic tool of merger trees by comparing halo assembly simulation analysed with three different halo finders—VELOCI raptor , AHF, and R ockstar —and their associated tree builders. Based on our analysis of the resulting dendrograms, we highlight how they have been used to motivate improvements to VELOCI raptor . The dendrogram software is publicly available online, at: hyspoulton/MergerTree-Dendrograms .
The XXL Survey
Publisher: EDP Sciences
Date: 20-11-2018
DOI: 10.1051/0004-6361/201731880
Abstract: We present the version of the point source catalogue of the XXL Survey that was used, in part, in the first series of XXL papers. In this paper we release, in our database in Milan and at CDS: (i) the X-ray source catalogue with 26 056 objects in two areas of 25 deg 2 with a flux limit (at 3 σ ) of ~10 −15 erg s −1 cm −2 in [0.5–2] keV, and ~ 3 × 10 −15 erg s −1 cm −2 in [2–10] keV, yielding a 90% completeness limit of 5.8 × 10 −15 and 3.8 × 10 −14 respectively (ii) the associated multiwavelength catalogues with candidate counterparts of the X-ray sources in the infrared, near-infrared, optical, and ultraviolet (plus spectroscopic redshift when available) and (iii) a catalogue of spectroscopic redshifts recently obtained in the southern XXL area. We also present the basic properties of the X-ray point sources and their counterparts. Other catalogues described in the second series of XXL papers will be released contextually, and will constitute the second XXLdata release.
FLASH pilot survey: detections of associated 21 cm H i absorption in GAMA galaxies at 0.42 < z < 1.00
Publisher: Oxford University Press (OUP)
Date: 18-08-2022
Abstract: We present the results of a search for associated 21 cm H i absorption at redshift 0.42 & z & 1.00 in radio-loud galaxies from three Galaxy And Mass Assembly (GAMA) survey fields. These observations were carried out as part of a pilot survey for the Australian SKA Pathfinder (ASKAP) First Large Absorption Survey in H i (FLASH). From a s le of 326 radio sources with 855.5 MHz peak flux density above 10 mJy, we detected two associated H i absorption systems, in SDSS J090331+010847 at z = 0.522 and SDSS J113622+004852 at z = 0.563. Both galaxies are massive (stellar mass $\\gt 10^{11}\\, \\mathrm{M}_\\odot$) and have optical spectra characteristic of luminous red galaxies, though spectral energy distribution fitting implies that SDSS J113622+004852 contains a dust-obscured starburst with star formation rate ∼69 M⊙ yr−1. The H i absorption lines have a high optical depth, with τpk of 1.77 ± 0.16 for SDSS J090331+010847 (the highest value for any z & 0.1 associated system found to date) and 0.14 ± 0.01 for SDSS J113622+004852. In the redshift range probed by our ASKAP observations, the detection rate for associated H i absorption lines (with τpk & 0.1 and at least 3σ significance) is $2.9_{-2.6}^{+9.7}$ per cent. Although the current s le is small, this rate is consistent with a trend seen in other studies for a lower detection rate of associated 21 cm H i absorption systems at higher redshift. We also searched for OH absorption lines at 0.67 & z & 1.34, but no detection was made in the 145 radio sources searched.
Forensic reconstruction of galaxy colour evolution and population characterization
Publisher: Oxford University Press (OUP)
Date: 04-02-2022
Abstract: Mapping the evolution of galaxy colours, from blue star forming to red passive systems, is fundamental to understand the processes involved in galaxy evolution. To this end, we reconstruct the colour evolution of low-redshift galaxies, combining stellar templates with star formation and metallicity histories of galaxies from the Galaxy And Mass Assembly survey and shark semi-analytical model. We use these colour histories to robustly characterize the evolution of red and blue galaxy populations over cosmic time. Using a Gaussian Mixture Model to characterize the colour distribution at any given epoch and stellar mass, we find both observations and simulations strongly favour a model with only two populations (blue and red), with no evidence for a third ‘green’ population. We map the evolution of mean, weight, and scatter of the blue and red populations as a function of both stellar mass and lookback time. Using our simulated galaxy catalogue as a testbed, we find that we can accurately recover galaxies colour histories up to a lookback time of ∼6 Gyr. We find that both populations show little change in the mean colour for low-mass galaxies, while the colours at the massive end become significantly redder with time. The stellar mass above which the galaxy population is predominantly red decreases by 0.3 dex in the last 5 Gyrs. We find a good agreement between observations and simulations, with the largest tension being that massive galaxies from shark are too blue (a known issue with many galaxy evolution models).
Galaxy And Mass Assembly (GAMA): The sSFR-M* relation part I – σsSFR-M* as a function of sample, SFR indicator and environment
Publisher: Oxford University Press (OUP)
Date: 03-11-2018
Galaxy And Mass Assembly (GAMA): the large-scale structure of galaxies and comparison to mock universes
Publisher: Oxford University Press (OUP)
Date: 14-12-2013
The Colors of Bulges and Disks in the Core and Outskirts of Galaxy Clusters
Publisher: American Astronomical Society
Date: 04-2021
Abstract: The role of the environment on the formation of S0 galaxies is still not well understood, specifically in the outskirts of galaxy clusters. We study eight low-redshift clusters, analyzing galaxy members up to cluster-centric distances of ∼2.5 R 200 . We perform 2D photometric bulge–disk decomposition in the g , r , and i bands from which we identify 469 double-component galaxies. We separately analyze the colors of the bulges and disks and their dependence on the projected cluster-centric distance and local galaxy density. For our s le of cluster S0 galaxies, we find that bulges are redder than their surrounding disks, show a significant color–magnitude trend, and have colors that do not correlate with environment metrics. On the other hand, the disks associated with our cluster S0s become significantly bluer with increasing cluster-centric radius but show no evidence for a color–magnitude relation. The disk color–radius relation is mainly driven by galaxies in the cluster core at 0 ≤ R / R 200 0.5. No significant difference is found for the disk colors of backsplash and infalling galaxies in the projected phase space (PPS). Beyond R 200 , the disk colors do not change with the local galaxy density, indicating that the colors of double-component galaxies are not affected by preprocessing. A significant color–density relation is observed for single-component disk-dominated galaxies beyond R 200 . We conclude that the formation of cluster S0 galaxies is primarily driven by cluster core processes acting on the disks, while evidence of preprocessing is found for single-component disk-dominated galaxies. We publicly release the data from the bulge–disk decomposition.
Herschel ★ -ATLAS: properties of dusty massive galaxies at low and high redshifts
Publisher: Oxford University Press (OUP)
Date: 03-05-2014
DOI: 10.1093/MNRAS/STU510
A numerical twist on the spin parameter, λR
Publisher: Oxford University Press (OUP)
Date: 18-11-2018
Dynamic Wisp Removal in JWST NIRCam Images
Publisher: IOP Publishing
Date: 08-2023
Abstract: The James Webb Space Telescope (JWST) near-infrared camera has been found to exhibit serious wisp-like structures in four of its eight short-wavelength detectors. The exact structure and strength of these wisps is highly variable with the position and orientation of JWST, so the use of static templates is non-optimal. Here we investigate a dynamic strategy to mitigate these wisps using long-wavelength reference images. Based on a suite of experiments where we embed a worst-case scenario median-stacked wisp into wisp-free images, we define suitable parameters for our wisp removal strategy. Using this setup we re-process wisp-affected public Prime Extragalactic Areas for Reionization and Lensing Science data in the North Ecliptic Pole Time Domain Field, resulting in significant visual improvement in our detector frames and reduced noise in the final stacked images.
The SAMI galaxy survey
Publisher: Oxford University Press (OUP)
Date: 21-11-2019
GAMA/DEVILS: cosmic star formation and AGN activity over 12.5 billion years
Publisher: Oxford University Press (OUP)
Date: 03-07-2023
Abstract: We use the Galaxy and Mass Assembly (GAMA) and the Deep Extragalactic Visible Legacy Survey (DEVILS) observational data sets to calculate the cosmic star formation rate (SFR) and active galactic nuclei (AGN) bolometric luminosity history (CSFH/CAGNH) over the last 12.5 billion years. SFRs and AGN bolometric luminosities were derived using the spectral energy distribution fitting code ProSpect, which includes an AGN prescription to self-consistently model the contribution from both AGN and stellar emission to the observed rest-frame ultra-violet to far-infrared photometry. We find that both the CSFH and CAGNH evolve similarly, rising in the early Universe up to a peak at look-back time ≈10 Gyr (z ≈ 2), before declining towards the present day. The key result of this work is that we find the ratio of CAGNH to CSFH has been flat ($\\approx 10^{42.5}\\, \\mathrm{erg \\, s^{-1}\\, {\\rm M}_{\\odot }^{-1}\\, yr}$) for 11 Gyr up to the present day, indicating that star formation and AGN activity have been coeval over this time period. We find that the stellar masses of the galaxies that contribute most to the CSFH and CAGNH are similar, implying a common cause, which is likely gas inflow. The depletion of the gas supply suppresses cosmic star formation and AGN activity equivalently to ensure that they have experienced similar declines over the last 10 Gyr. These results are an important milestone for reconciling the role of star formation and AGN activity in the life cycle of galaxies.
Galaxy And Mass Assembly (GAMA): the wavelength-dependent sizes and profiles of galaxies revealed by MegaMorph
Publisher: Oxford University Press (OUP)
Date: 08-05-2014
DOI: 10.1093/MNRAS/STU632
ProFuse
Publisher: Oxford University Press (OUP)
Date: 15-04-2022
Abstract: We present the new ProFuse r package, a simultaneous spectral (ultraviolet to far-infrared) and spatial structural decomposition tool that produces physical models of galaxies and their components. This combines the functionality of the recently released ProFound (for automatic source extraction), ProFit (for extended source profiling), and ProSpect (for stellar population modelling) software packages. The key novelty of ProFuse is that it generates images using a self-consistent model for the star formation and metallicity history of the bulge and disc separately, and uses target images across a range of wavelengths to define the model likelihood and optimize our physical galaxy reconstruction. The first part of the paper explores the ProFuse approach in detail, and compares results to published structural and stellar population properties. The latter part of the paper applies ProFuse to 6664 z & 0.06 GAMA galaxies. Using re-processed ugriZYJHKs imaging we extract structural and stellar population properties for bulges and discs in parallel. As well as producing true stellar mass based mass–size relationships, we further extend this correlation to explore the third dimensions of age and gas phase metallicity. The discs in particular demonstrate strong co-dependency between mass–size–age in a well-defined plane, where at a given disc stellar mass younger discs tend to be larger. These findings are in broad agreement with work at higher redshift, suggesting discs that formed earlier are physically smaller.
MEASUREMENTS OF EXTRAGALACTIC BACKGROUND LIGHT FROM THE FAR UV TO THE FAR IR FROM DEEP GROUND- AND SPACE-BASED GALAXY COUNTS
Publisher: American Astronomical Society
Date: 12-08-2016
Galaxy And Mass Assembly (GAMA): the dependence of the galaxy luminosity function on environment, redshift and colour
Publisher: Oxford University Press (OUP)
Date: 15-10-2014
Major mergers between dark matter haloes – I. Predictions for size, shape, and spin
Publisher: Oxford University Press (OUP)
Date: 11-05-2019
The SAMI Galaxy Survey: Early Data Release
Publisher: Oxford University Press (OUP)
Date: 20-11-2015
Galaxy And Mass Assembly (GAMA): the halo mass of galaxy groups from maximum-likelihood weak lensing
Publisher: Oxford University Press (OUP)
Date: 19-11-2014
Major mergers between dark matter haloes – II. Profile and concentration changes
Publisher: Oxford University Press (OUP)
Date: 11-05-2019
ProFound: Source Extraction and Application to Modern Survey Data
Publisher: Oxford University Press (OUP)
Date: 23-02-2018
DOI: 10.1093/MNRAS/STY440
Climbing halo merger trees with TreeFrog
Publisher: Cambridge University Press (CUP)
Date: 2019
DOI: 10.1017/PASA.2019.18
Abstract: We present T ree F rog , a massively parallel halo merger tree builder that is capable comparing different halo catalogues and producing halo merger trees. The code is written in c++11, use the MPI and OpenMP API’s for parallelisation, and includes python tools to read/manipulate the data products produced. The code correlates binding energy sorted particle ID lists between halo catalogues, determining optimal descendant rogenitor matches using multiple snapshots, a merit function that maximises the number of shared particles using pseudo-radial moments, and a scheme for correcting halo merger tree pathologies. Focusing on VELOCI raptor catalogues for this work, we demonstrate how searching multiple snapshots spanning a dynamical time significantly reduces the number of stranded halos, those lacking a descendant or a progenitor, critically correcting poorly resolved halos. We present a new merit function that improves the distinction between primary and secondary progenitors, reducing tree pathologies. We find FOF accretion rates and merger rates show similar mass ratio dependence. The model merger rates from Poole, et al. [2017, 472, 3659] agree with the measured net growth of halos through mergers.
Galaxy And Mass Assembly: the evolution of the cosmic spectral energy distribution from z = 1 to z = 0
Publisher: Oxford University Press (OUP)
Date: 25-05-2017
Hunting for galaxies and halos in simulations with VELOCIraptor
Publisher: Cambridge University Press (CUP)
Date: 2019
DOI: 10.1017/PASA.2019.12
Abstract: We present VELOCI raptor , a massively parallel galaxy/(sub)halo finder that is also capable of robustly identifying tidally disrupted objects and separate stellar halos from galaxies. The code is written in C++11, use the Message Passing Interface (MPI) and OpenMP Application Programming Interface (API) for parallelisation, and includes python tools to read/manipulate the data products produced. We demonstrate the power of the VELOCI raptor (sub)halo finder, showing how it can identify subhalos deep within the host that have negligible density contrasts to their parent halo. We find a subhalo mass-radial distance dependence: large subhalos with mass ratios of ≳10 −2 are more common in the central regions than smaller subhalos, a result of dynamical friction and low tidal mass loss rates. This dependence is completely absent in (sub)halo finders in common use, which generally search for substructure in configuration space, yet is present in codes that track particles belonging to halos as they fall into other halos, such as hbt +. VELOCI raptor largely reproduces the dependence seen without tracking, finding a similar radial dependence to hbt + in well-resolved halos from our limited resolution fiducial simulation.
THE EXTENDED STELLAR COMPONENT OF GALAXIES THE NATURE OF DARK MATTER
Publisher: American Astronomical Society
Date: 28-06-2016
Galactic googly: the rotation-metallicity bias in the inner stellar halo of the Milky Way
Publisher: Oxford University Press (OUP)
Date: 07-06-2017
Galaxy And Mass Assembly (GAMA): ugrizYJHK Sérsic luminosity functions and the cosmic spectral energy distribution by Hubble type
Publisher: Oxford University Press (OUP)
Date: 12-02-2014
Drivers of asymmetry in synthetic H i emission-line profiles of galaxies in the eagle simulation
Publisher: Oxford University Press (OUP)
Date: 04-12-2021
Abstract: We study the shapes of spatially integrated $\\rm{H}\\, \\small {{I}}$ emission-line profiles of galaxies in the eagle simulation using three separate measures of the profile’s asymmetry. We show that the subset of eagle galaxies whose gas fractions and stellar masses are consistent with those in the xGASS survey also have similar $\\rm{H}\\, \\small {{I}}$ line asymmetries. Central galaxies with symmetric $\\rm{H}\\, \\small {{I}}$ line profiles typically correspond to rotationally supported $\\rm{H}\\, \\small {{I}}$ and stellar discs, but those with asymmetric line profiles may or may not correspond to dispersion-dominated systems. Galaxies with symmetric $\\rm{H}\\, \\small {{I}}$ emission lines are, on average, more gas rich than those with asymmetric lines, and also exhibit systematic differences in their specific star formation rates, suggesting that turbulence generated by stellar or AGN feedback may be one factor contributing to $\\rm{H}\\, \\small {{I}}$ line asymmetry. The line asymmetry also correlates strongly with the dynamical state of a galaxy’s host dark matter halo: older, more relaxed haloes host more-symmetric galaxies than those hosted by unrelaxed ones. At fixed halo mass, asymmetric centrals tend to be surrounded by a larger number of massive subhaloes than their symmetric counterparts, and also experience higher rates of gas accretion and outflow. At fixed stellar mass, central galaxies have, on average, more symmetric $\\rm{H}\\, \\small {{I}}$ emission lines than satellites for the latter, ram pressure and tidal stripping are significant sources of asymmetry.
EPOCHS VII
Publisher: Oxford University Press (OUP)
Date: 07-08-2023
Abstract: We present an analysis of a s le of robust high-redshift galaxies selected from the ‘blank’ fields of the Prime Extragalactic Areas for Reionization Science (PEARLS) survey and Early Release Observations (ERO) data from JWST with the aim of selecting candidate high-redshift active galactic nuclei (AGN). Sources were identified from this parent s le using a threefold selection procedure, which includes spectral energy distribution (SED) fitting to identify sources that are best fitted by AGN SED templates, a further selection based on the relative performance of AGN and non-AGN models, and finally morphological fitting to identify compact sources of emission, resulting in a purity-oriented procedure. Using this procedure, we identify a s le of nine AGN candidates at 6.5 & z & 12, from which we constrain their physical properties as well as measure a lower bound on the AGN fraction in this redshift range of 5 ± 1 per cent. As this is an extreme lower limit due to our focus on purity and our SEDs being calibrated for unobscured Type 1 AGN, this demonstrates that AGN are perhaps quite common at this early epoch. The rest-frame UV colours of our candidate objects suggest that these systems are potentially candidate obese black hole galaxies (OBGs). We also investigate Chandra and VLA maps of these areas from which we calculate detection limits. Of note is a z = 11.9 candidate source exhibiting an abrupt morphological shift in the reddest band as compared to bluer bands, indicating a potential merger or an unusually strong outflow.
GAMA/H-ATLAS: linking the properties of submm detected and undetected early-type galaxies – I. z ≤ 0.06 sample
Publisher: Oxford University Press (OUP)
Date: 20-03-0031
DOI: 10.1093/MNRAS/STT310
The SAMI Galaxy Survey
Publisher: Oxford University Press (OUP)
Date: 30-11-2023
Dark matter halo properties of GAMA galaxy groups from 100 square degrees of KiDS weak lensing data
Publisher: Oxford University Press (OUP)
Date: 06-08-2015
FLASH early science - Discovery of an intervening H I 21-cm absorber from an ASKAP survey of the GAMA 23 field
Publisher: Oxford University Press (OUP)
Date: 09-04-2020
Abstract: We present early science results from the First Large Absorption Survey in H i (FLASH), a spectroscopically blind survey for 21-cm absorption lines in cold hydrogen (H i) gas at cosmological distances using the Australian Square Kilometre Array Pathfinder (ASKAP). We have searched for H i absorption towards 1253 radio sources in the GAMA 23 field, covering redshifts between z = 0.34 and 0.79 over a sky area of approximately 50 deg2. In a purely blind search, we did not obtain any detections of 21-cm absorbers above our reliability threshold. Assuming a fiducial value for the H i spin temperature of Tspin = 100 K and source covering fraction cf = 1, the total comoving absorption path-length sensitive to all D ed Lyman α Absorbers (DLAs NH i ≥ 2 × 1020 cm−2) is ΔX = 6.6 ± 0.3 (Δz = 3.7 ± 0.2) and super-DLAs (NH i ≥ 2 × 1021 cm−2) is ΔX = 111 ± 6 (Δz= 63 ± 3). We estimate upper limits on the H i column density frequency distribution function that are consistent with measurements from prior surveys for redshifted optical DLAs, and nearby 21-cm emission and absorption. By cross-matching our s le of radio sources with optical spectroscopic identifications of galaxies in the GAMA 23 field, we were able to detect 21-cm absorption at z = 0.3562 towards NVSS J224500−343030, with a column density of $N_{\\rm H\\,\\small{I}} = (1.2 \\pm 0.1) \\times 10^{20}\\, (T_{\\rm spin}/100\\, \\mathrm{K})$ cm−2. The absorber is associated with GAMA J22450.05−343031.7, a massive early-type galaxy at an impact parameter of 17 kpc with respect to the radio source and which may contain a massive (MH i ≳ 3 × 109 M⊙) gas disc. Such gas-rich early types are rare, but have been detected in the nearby Universe.
Galaxy And Mass Assembly (GAMA): gas fuelling of spiral galaxies in the local Universe II. – direct measurement of the dependencies on redshift and host halo mass of stellar mass growth in central dis
Publisher: Oxford University Press (OUP)
Date: 16-03-2018
DOI: 10.1093/MNRAS/STY688
Galaxy and Mass Assembly (GAMA): formation and growth of elliptical galaxies in the group environment
Publisher: Oxford University Press (OUP)
Date: 22-02-2017
DOI: 10.1093/MNRAS/STX441
The SAMI Galaxy Survey: The cluster redshift survey, target selection and cluster properties
Publisher: Oxford University Press (OUP)
Date: 08-03-2017
DOI: 10.1093/MNRAS/STX562
User identity issues in mashups for learning experiences using IMS Learning Design
Publisher: Inderscience Publishers
Date: 2011
Galaxy And Mass Assembly (GAMA): the mass-metallicity relationship
Publisher: EDP Sciences
Date: 31-10-2012
Galaxy And Mass Assembly (GAMA): the unimodal nature of the dwarf galaxy population
Publisher: Oxford University Press (OUP)
Date: 02-12-2014
From rest-frame luminosity functions to observer-frame colour distributions: tackling the next challenge in cosmological simulations
Publisher: Oxford University Press (OUP)
Date: 11-07-2020
Abstract: Galaxy spectral energy distributions (SEDs) remain among the most challenging yet informative quantities to reproduce in simulations due to the large and complex mixture of physical processes that shape the radiation output of a galaxy. With the increasing number of surveys utilizing broad-band colours as part of their target selection criteria, the production of realistic SEDs in simulations is necessary for assisting in survey design and interpretation of observations. The recent success in reproducing the observed luminosity functions (LFs) from far-ultraviolet (UV) to far-infrared (IR), using the state-of-the-art semi-analytic model shark and the SED generator ProSpect, represents a critical step towards better galaxy colour predictions. We show that with shark and ProSpect we can closely reproduce the optical colour distributions observed in the panchromatic Galaxy And Mass Assembly (GAMA) survey. The treatment of feedback, star formation, central–satellite interactions, and radiation reprocessing by dust are critical for this achievement. The first three processes create a bimodal distribution, while dust attenuation defines the location and shape of the blue and red populations. While a naive comparison between observation and simulations displays the known issue of overquenching of satellite galaxies, the introduction of empirically motivated observational errors and classification from the same group finder used in GAMA greatly reduces this tension. The introduction of random reassignment of ${\\sim} 15{{\\ \\rm per\\ cent}}$ of centrals/satellites as satellites/centrals on the simulation classification closely resembles the outcome of the group finder, providing a computationally less intensive method to compare simulations with observations.
The masses of satellites in GAMA galaxy groups from 100 square degrees of KiDS weak lensing data
Publisher: Oxford University Press (OUP)
Date: 28-10-2015
Galaxy And Mass Assembly (GAMA): stellar mass estimates
Publisher: Oxford University Press (OUP)
Date: 18-11-2011
WALLABY early science - I. The NGC 7162 galaxy group
Publisher: Oxford University Press (OUP)
Date: 29-10-2019
Multiwavelength scaling relations in galaxy groups: a detailed comparison of GAMA and KiDS observations to BAHAMAS simulations
Publisher: Oxford University Press (OUP)
Date: 30-07-2018
GAMA/H-ATLAS: the ultraviolet spectral slope and obscuration in galaxies
Publisher: Oxford University Press (OUP)
Date: 27-06-2011
Measuring the Growth Rate of Structure with Type IA Supernovae from LSST
Publisher: American Astronomical Society
Date: 29-09-2017
DEVILS: cosmic evolution of SED-derived metallicities and their connection to star formation histories
Publisher: Oxford University Press (OUP)
Date: 26-10-2022
Abstract: Gas-phase metallicities of galaxies are typically measured through auroral or nebular emission lines, but metallicity also leaves an imprint on the overall spectral energy distribution (SED) of a galaxy and can be estimated through SED fitting. We use the ProSpect SED fitting code with a flexible parametric star formation history and an evolving metallicity history to self-consistently measure metallicities, stellar mass, and other galaxy properties for $\\sim 90\\, 000$ galaxies from the Deep Extragalactic VIsible Legacy Survey (DEVILS) and Galaxy and Mass Assembly (GAMA) survey. We use these to trace the evolution of the mass–metallicity relation (MZR) and show that the MZR only evolves in normalization by $\\sim 0.1\\,$dex at stellar mass $M_\\star = 10^{10.5}\\, \\mathrm{M}_\\odot$. We find no difference in the MZR between galaxies with and without SED evidence of active galactic nuclei emission at low redshifts ($z$ & 0.3). Our results suggest an anticorrelation between metallicity and star formation activity at fixed stellar mass for galaxies with $M_\\star \\gt 10^{10.5}\\, \\mathrm{M}_\\odot$ for $z$ & 0.3. Using the star formation histories extracted using ProSpect we explore higher order correlations of the MZR with properties of the star formation history including age, width, and shape. We find that at a given stellar mass, galaxies with higher metallicities formed most of their mass over shorter time-scales, and before their peak star formation rate. This work highlights the value of exploring the connection of a galaxy’s current gas-phase metallicity to its star formation history in order to understand the physical processes shaping the MZR.
GAMA/G10-COSMOS/3D-HST: Evolution of the galaxy stellar mass function over 12.5 Gyr
Publisher: Oxford University Press (OUP)
Date: 06-08-2018
GAMA/H-ATLAS: THE DUST OPACITY–STELLAR MASS SURFACE DENSITY RELATION FOR SPIRAL GALAXIES
Publisher: American Astronomical Society
Date: 07-03-2013
Herschel ★ -ATLAS/GAMA: SDSS cross-correlation induced by weak lensing
Publisher: Oxford University Press (OUP)
Date: 26-06-2014
Galaxy And Mass Assembly: evolution of the Hα luminosity function and star formation rate density up to z < 0.35
Publisher: Oxford University Press (OUP)
Date: 29-06-2013
DOI: 10.1093/MNRAS/STT890
Galaxy And Mass Assembly (GAMA): bivariate functions of Hα star-forming galaxies
Publisher: Oxford University Press (OUP)
Date: 19-12-2014
A New Wide-field Infrared Survey Explorer Calibration of Stellar Mass
Publisher: American Astronomical Society
Date: 04-2023
Abstract: We derive new empirical scaling relations between Wide-field Infrared Survey Explorer (WISE) mid-IR (MIR) galaxy photometry and well-determined stellar masses from spectral energy distribution modeling of a suite of optical–infrared photometry provided by the Data Release 4 (DR4) Catalog of the GAMA-KiDS-VIKING survey of the southern G23 field. The MIR source extraction and characterization are drawn from the WISE Extended Source Catalogue and the archival ALLWISE catalog, combining both resolved and compact galaxies in the G23 s le to a redshift of 0.15. Three scaling relations are derived: W1 3.4 μ m luminosity versus stellar mass, and WISE W1–W2, W1–W3 colors versus mass-to-light ratio ( M / L , sensitive to a variety of galaxy types from passive to star-forming). For each galaxy in the s le, we then derive the combined stellar mass from these scaling relations, producing M ⋆ estimates with better than ∼25%–30% accuracy for galaxies with 9 M ⊙ and %–50% for lower-luminosity dwarf galaxies. We also provide simple prescriptions for rest-frame corrections and estimating stellar masses using only the W1 flux and the W1–W2 color, making stellar masses more accessible to users of the WISE data. Given a redshift or distance, these new scaling relations will enable stellar mass estimates for any galaxy in the sky detected by WISE with high fidelity across a range of M / L ratios.
H-ATLAS/GAMA and HeViCS – dusty early-type galaxies in different environments
Publisher: Oxford University Press (OUP)
Date: 29-06-2015
Extracting galaxy merger time-scales II: a new fitting formula
Publisher: Oxford University Press (OUP)
Date: 23-10-2021
Abstract: Predicting the merger time-scale (τmerge) of merging dark matter haloes, based on their orbital parameters and the structural properties of their hosts, is a fundamental problem in gravitational dynamics that has important consequences for our understanding of cosmological structure formation and galaxy formation. Previous models predicting τmerge have shown varying degrees of success when compared to the results of cosmological N-body simulations. We build on this previous work and propose a new model for τmerge that draws on insights derived from these simulations. We find that published predictions can provide reasonable estimates for τmerge based on orbital properties at infall, but tend to underpredict τmerge inside the host virial radius (R200) because tidal stripping is neglected, and overpredict it outside R200 because the host mass is underestimated. Furthermore, we find that models that account for orbital angular momentum via the circular radius Rcirc underpredict (overpredict) τmerge for bound (unbound) systems. By fitting for the dependence of τmerge on various orbital and host halo properties, we derive an improved model for τmerge that can be applied to a merging halo at any point in its orbit. Finally, we discuss briefly the implications of our new model for τmerge for semi-analytical galaxy formation modelling.
GAMA/DEVILS: constraining the cosmic star formation history from improved measurements of the 0.3–2.2 μm extragalactic background light
Publisher: Oxford University Press (OUP)
Date: 26-02-2021
Abstract: We present a revised measurement of the optical extragalactic background light (EBL), based on the contribution of resolved galaxies to the integrated galaxy light (IGL). The cosmic optical background radiation (COB), encodes the light generated by star formation, and provides a wealth of information about the cosmic star formation history (CSFH). We combine wide and deep galaxy number counts from the Galaxy And Mass Assembly survey (GAMA) and Deep Extragalactic VIsible Legacy Survey (DEVILS), along with the Hubble Space Telescope (HST) archive and other deep survey data sets, in nine multiwavelength filters to measure the COB in the range from 0.35 μm to 2.2 μm. We derive the luminosity density in each band independently and show good agreement with recent and complementary estimates of the optical-EBL from very high-energy (VHE) experiments. Our error analysis suggests that the IGL and γ-ray measurements are now fully consistent to within $\\sim 10{{\\ \\rm per\\ cent}}$, suggesting little need for any additional source of diffuse light beyond the known galaxy population. We use our revised IGL measurements to constrain the CSFH, and place litude constraints on a number of recent estimates. As a consistency check, we can now demonstrate convincingly, that the CSFH, stellar mass growth, and the optical-EBL provide a fully consistent picture of galaxy evolution. We conclude that the peak of star formation rate lies in the range 0.066–0.076 M⊙ yr−1 Mpc−3 at a lookback time of 9.1 to 10.9 Gyr.
The variation of the galaxy luminosity function with group properties
Publisher: Oxford University Press (OUP)
Date: 21-04-2010
JWST’s PEARLS: A JWST/NIRCam View of ALMA Sources
Publisher: American Astronomical Society
Date: 2023
Abstract: We report the results of James Webb Space Telescope/NIRCam observations of 19 (sub)millimeter sources detected by the Atacama Large Millimeter Array (ALMA). The accurate ALMA positions allowed unambiguous identifications of their NIRCam counterparts. Taking gravitational lensing into account, these represent 16 distinct galaxies in three fields and constitute the largest s le of its kind to date. The counterparts’ spectral energy distributions cover from rest-frame ultraviolet to near-IR and provide photometric redshifts (1 z 4.5) and stellar masses ( M * 10 10.5 M ⊙ ), which are similar to submillimeter galaxies (SMGs) studied previously. However, our s le is fainter in (sub)millimeter than the classic SMG s les are, and our sources exhibit a wider range of properties. They have dust-embedded star formation rates as low as 10 M ⊙ yr −1 , and the sources populate both the star-forming main sequence and the quiescent categories. The deep NIRCam data allow us to study the rest-frame near-IR morphologies. Excluding two multiply imaged systems and one quasar, the majority of the remaining sources are disk-like and show either little or no disturbance. This suggests that secular growth is a potential route for the assembly of high-mass disk galaxies. While a few objects have large disks, the majority have small disks (median half-mass radius of 1.6 kpc). At this time, it is unclear whether this is due to the prevalence of small disks at these redshifts or some unknown selection effects of deep ALMA observations. A larger s le of ALMA sources with NIRCam observations will be able to address this question.
Galaxy and Mass Assembly (GAMA): Impact of the Group Environment on Galaxy Star Formation
Publisher: American Astronomical Society
Date: 16-04-2018
Galaxy And Mass Assembly: the 1.4 GHz SFR indicator, SFR–M*relation and predictions for ASKAP–GAMA
Publisher: Oxford University Press (OUP)
Date: 30-11-2016
HALOGEN: a tool for fast generation of mock halo catalogues
Publisher: Oxford University Press (OUP)
Date: 29-04-2015
DOI: 10.1093/MNRAS/STV711
Galaxy and Mass Assembly (GAMA): the star formation rate dependence of the stellar initial mass function
Publisher: Oxford University Press (OUP)
Date: 04-07-2011
Hydra II: Characterisation of Aegean, Caesar, ProFound, PyBDSF, and Selavy source finders
Publisher: Cambridge University Press (CUP)
Date: 2023
DOI: 10.1017/PASA.2023.29
Abstract: We present a comparison between the performance of a selection of source finders (SFs) using a new software tool called Hydra. The companion paper, Paper I, introduced the Hydra tool and demonstrated its performance using simulated data. Here we apply Hydra to assess the performance of different source finders by analysing real observational data taken from the Evolutionary Map of the Universe (EMU) Pilot Survey. EMU is a wide-field radio continuum survey whose primary goal is to make a deep ( $20\\mu$ Jy/beam RMS noise), intermediate angular resolution ( $15^{\\prime\\prime}$ ), 1 GHz survey of the entire sky south of $+30^{\\circ}$ declination, and expecting to detect and catalogue up to 40 million sources. With the main EMU survey it is highly desirable to understand the performance of radio image SF software and to identify an approach that optimises source detection capabilities. Hydra has been developed to refine this process, as well as to deliver a range of metrics and source finding data products from multiple SFs. We present the performance of the five SFs tested here in terms of their completeness and reliability statistics, their flux density and source size measurements, and an exploration of case studies to highlight finder-specific limitations.
Galaxy and Mass Assembly (GAMA): halo formation times and halo assembly bias on the cosmic web
Publisher: Oxford University Press (OUP)
Date: 14-06-2017
Galaxy and mass assembly (GAMA): the inferred mass–metallicity relation from z = 0 to 3.5 via forensic SED fitting
Publisher: Oxford University Press (OUP)
Date: 03-2021
Abstract: We analyse the metallicity histories of ∼4500 galaxies from the GAMA survey at z & 0.06 modelled by the SED-fitting code ProSpect using an evolving metallicity implementation. These metallicity histories, in combination with the associated star formation histories, allow us to analyse the inferred gas-phase mass–metallicity relation. Furthermore, we extract the mass–metallicity relation at a sequence of epochs in cosmic history, to track the evolving mass–metallicity relation with time. Through comparison with observations of gas-phase metallicity over a large range of redshifts, we show that, remarkably, our forensic SED analysis has produced an evolving mass–metallicity relationship that is consistent with observations at all epochs. We additionally analyse the three-dimensional mass–metallicity–SFR space, showing that galaxies occupy a clearly defined plane. This plane is shown to be subtly evolving, displaying an increased tilt with time caused by general enrichment, and also the slowing down of star formation with cosmic time. This evolution is most apparent at lookback times greater than 7 Gyr. The trends in metallicity recovered in this work highlight that the evolving metallicity implementation used within the SED-fitting code ProSpect produces reasonable metallicity results over the history of a galaxy. This is expected to provide a significant improvement to the accuracy of the SED-fitting outputs.
Galaxy And Mass Assembly (GAMA): linking star formation histories and stellar mass growth
Publisher: Oxford University Press (OUP)
Date: 02-07-2013
Galaxy and mass assembly (GAMA): projected galaxy clustering
Publisher: Oxford University Press (OUP)
Date: 13-10-2015
GALAXY AND MASS ASSEMBLY (GAMA): MID-INFRARED PROPERTIES AND EMPIRICAL RELATIONS FROMWISE
Publisher: American Astronomical Society
Date: 31-01-2014
Herschel-ATLAS: far-infrared properties of radio-selected galaxies★
Publisher: Oxford University Press (OUP)
Date: 29-10-2010
Galaxy And Mass Assembly (GAMA): in search of Milky Way Magellanic Cloud analogues
Publisher: Oxford University Press (OUP)
Date: 27-06-2012
SKYSURF: Constraints on Zodiacal Light and Extragalactic Background Light through Panchromatic HST All-sky Surface-brightness Measurements: II. First Limits on Diffuse Light at 1.25, 1.4, and 1.6 μm
Publisher: American Astronomical Society
Date: 04-10-2022
Abstract: We present the first results from the HST Archival Legacy project “SKYSURF.” As described in Windhorst et al., SKYSURF utilizes the large HST archive to study the diffuse UV, optical, and near-IR backgrounds and foregrounds in detail. Here, we utilize SKYSURF’s first sky-surface-brightness measurements to constrain the level of near-IR diffuse Extragalactic Background Light (EBL) in three near-IR filters (F125W, F140W, and F160W). This is done by comparing our preliminary sky measurements of ,000 images to zodiacal light models, carefully selecting the darkest images to avoid contamination from stray light. Our sky-surface-brightness measurements have been verified to an accuracy of better than 1%, which when combined with systematic errors associated with HST, results in sky-brightness uncertainties of ∼ 2%–4% ≃ 0.005 MJy sr −1 in each image. When compared to the Kelsall et al. zodiacal model, an isotropic diffuse background of ∼30 nW m −2 sr −1 remains, whereas using the Wright zodiacal model results in no discernible diffuse background. Based primarily on uncertainties in the foreground model subtraction, we present limits on the amount of diffuse EBL of 29, 40, and 29 nW m −2 sr −1 , for F125W, F140W, and F160W, respectively. While this light is generally isotropic, our modeling at this point does not distinguish between a cosmological origin or a solar system origin (such as a dim, diffuse, spherical cloud of cometary dust).
Herschel-ATLAS: Evolution of the 250 µm luminosity function out to z=0.5
Publisher: EDP Sciences
Date: 07-2010
SIMSPIN - Constructing mock IFS kinematic data cubes
Publisher: Cambridge University Press (CUP)
Date: 2020
DOI: 10.1017/PASA.2020.8
Abstract: We present SimSpin , a new, public, software framework for generating integral field spectroscopy (IFS) data cubes from N -body/hydrodynamical simulations of galaxies, which can be compared directly with observational datasets. SimSpin provides a consistent method for studying a galaxy’s stellar component. It can be used to explore how observationally inferred measurements of kinematics, such as the spin parameter $\\lambda_R$ , are impacted by the effects of, for ex le, inclination, seeing conditions, distance. SimSpin is written in R and has been designed to be highly modular, flexible, and extensible. It is already being used by the astrophysics community to generate IFS-like cubes and FITS files for direct comparison of simulations to observations. In this paper, we explain the conceptual framework of SimSpin how it is implemented in R and we demonstrate SimSpin ’s current capabilities, providing as an ex le a brief investigation of how numerical resolution affects how reliably we can recover the intrinsic stellar kinematics of a simulated galaxy.
Galaxy And Mass Assembly: resolving the role of environment in galaxy evolution
Publisher: Oxford University Press (OUP)
Date: 04-09-2013
The XXL Survey. XLII. The LX − σv relation of galaxy groups and clusters detected in the XXL and GAMA surveys
Publisher: Oxford University Press (OUP)
Date: 02-02-2022
Abstract: The XXL Survey is the largest homogeneous survey carried out with XMM-Newton. Covering an area of 50 deg2, the survey contains several hundred galaxy clusters out to a redshift of ≈2, above an X-ray flux limit of ∼6 × 10−15 er g cm−2 s−1. The GAMA spectroscopic survey of ∼300 000 galaxies covers ≈286 deg2, down to an r-band magnitude of r & 19.8 mag. The region of overlap of these two surveys (covering 14.6 deg2) represents an ideal opportunity to study clusters selected via two independent selection criteria. Generating two independently selected s les of clusters, one drawn from XXL (spanning a redshift range 0.05 ≤ z ≤ 0.3) and another from GAMA (0.05 ≤ z ≤ 0.2), both spanning 0.2 ≲ M500 ≲ 5 × 1014 M⊙, we investigate the relationship between X-ray luminosity and velocity dispersion (LX − σv relation). Comparing the LX − σv relation between the X-ray selected and optically selected s les, when not accounting for the X-ray selection, we find that the scatter of the X-ray selected s le is 2.7 times higher than the optically selected s le (at the 3.7σ level). Accounting for the X-ray selection to model the LX − σv relation, we find that the difference in the scatter increases (with the X-ray selected s le having a scatter 3.4 times larger than the optically selected s le). Although the scatter of the optically selected s le is lower, we find 13 optically selected GAMA groups undetected in X-rays. Inspection of the difference in magnitude between the first and second brightest galaxies in the cluster, and a stacked X-ray image of these 13 groups, suggests that these are young systems still in the process of forming.
GAMA: towards a physical understanding of galaxy formation
Publisher: Oxford University Press (OUP)
Date: 10-2009
Galaxy And Mass Assembly (GAMA): Panchromatic Data Release (far-UV–far-IR) and the low-zenergy budget
Publisher: Oxford University Press (OUP)
Date: 03-12-2015
4MOST: 4-metre Multi-Object Spectroscopic Telescope
Publisher: SPIE
Date: 24-07-2014
DOI: 10.1117/12.2055826
JWST’s PEARLS: A new lens model for ACT-CL J0102−4915, “El Gordo,” and the first red supergiant star at cosmological distances discovered by JWST
Publisher: EDP Sciences
Date: 23-03-2023
DOI: 10.1051/0004-6361/202245238
Abstract: The first James Webb Space Telescope (JWST) data on the massive colliding cluster El Gordo allow for 23 known families of multiply lensed images to be confirmed and for eight new members of these families to be identified. Based on these families, which have been confirmed spectroscopically by MUSE, we derived an initial lens model. This model guided the identification of 37 additional families of multiply lensed galaxies, among which 28 are entirely new systems, and nine were previously known. The initial lens model determined geometric redshifts for the 37 new systems. The geometric redshifts agree reasonably well with spectroscopic or photometric redshifts when those are available. The geometric redshifts enable two additional models that include all 60 families of multiply lensed galaxies spanning a redshift range 2 z 6. The derived dark-matter distribution confirms the double-peak configuration of mass found by earlier work with the southern and northern clumps having similar masses. We confirm that El Gordo is the most massive known cluster at z 0.8 and has an estimated virial mass close the maximum mass allowed by standard cosmological models. The JWST images also reveal the presence of small-mass perturbers that produce small lensing distortions. The smallest of these is consistent with being a dwarf galaxy at z = 0.87 and has an estimated mass of 3.8 × 10 9 M ⊙ , making it the smallest substructure found at z 0.5. The JWST images also show several candidate caustic-crossing events. One of them is detected at high significance at the expected position of the critical curve and is likely a red supergiant star at z = 2.1878. This would be the first red supergiant found at cosmological distances. The cluster lensing should magnify background objects at z 6, making more of them visible than in blank fields of a similar size, but there appears to be a deficiency of such objects.
An Empirical Mass Function Distribution
Publisher: American Astronomical Society
Date: 27-02-2018
The need for speed
Publisher: Oxford University Press (OUP)
Date: 10-01-2018
DOI: 10.1093/MNRAS/STY082
Galaxy And Mass Assembly (GAMA): galaxy close pairs, mergers and the future fate of stellar mass
Publisher: Oxford University Press (OUP)
Date: 18-09-2014
Galaxy and Mass Assembly (GAMA): survey diagnostics and core data release
Publisher: Oxford University Press (OUP)
Date: 02-03-2011
Tracing Hi Beyond the Local Universe
Publisher: Cambridge University Press (CUP)
Date: 2017
DOI: 10.1017/PASA.2017.31
Abstract: The SKA and its pathfinders will enable studies of H i emission at higher redshifts than ever before. In moving beyond the local Universe, this will require the use of cosmologically appropriate formulae that have traditionally been simplified to their low-redshift approximations. In this paper, we summarise some of the most important relations for tracing H i emission in the SKA era, and present an online calculator to assist in the planning and analysis of observations ( hifi.icrar.org ).
Galaxy And Mass Assembly (GAMA): AUTOZ spectral redshift measurements, confidence and errors
Publisher: Oxford University Press (OUP)
Date: 20-05-2014
DOI: 10.1093/MNRAS/STU727
The XXL Survey
Publisher: EDP Sciences
Date: 20-11-2018
DOI: 10.1051/0004-6361/201731606
Abstract: Context. In the currently debated context of using clusters of galaxies as cosmological probes, the need for well-defined cluster s les is critical. Aims. The XXL Survey has been specifically designed to provide a well characterised s le of some 500 X-ray detected clusters suitable for cosmological studies. The main goal of present article is to make public and describe the properties of the cluster catalogue in its present state, as well as of associated catalogues of more specific objects such as super-clusters and fossil groups. Methods. Following from the publication of the hundred brightest XXL clusters, we now release a s le containing 365 clusters in total, down to a flux of a few 10 −15 erg s −1 cm −2 in the [0.5–2] keV band and in a 1′ aperture. This release contains the complete subset of clusters for which the selection function is well determined plus all X-ray clusters which are, to date, spectroscopically confirmed. In this paper, we give the details of the follow-up observations and explain the procedure adopted to validate the cluster spectroscopic redshifts. Considering the whole XXL cluster s le, we have provided two types of selection, both complete in a particular sense: one based on flux-morphology criteria, and an alternative based on the [0.5–2] keV flux within 1 arcmin of the cluster centre. We have also provided X-ray temperature measurements for 80% of the clusters having a flux larger than 9 × 10 −15 erg s −1 cm −2 . Results. Our cluster s le extends from z ~ 0 to z ~ 1.2, with one cluster at z ~ 2. Clusters were identified through a mean number of six spectroscopically confirmed cluster members. The largest number of confirmed spectroscopic members in a cluster is 41. Our updated luminosity function and luminosity–temperature relation are compatible with our previous determinations based on the 100 brightest clusters, but show smaller uncertainties. We also present an enlarged list of super-clusters and a s le of 18 possible fossil groups. Conclusions. This intermediate publication is the last before the final release of the complete XXL cluster catalogue when the ongoing C2 cluster spectroscopic follow-up is complete. It provides a unique inventory of medium-mass clusters over a 50 deg 2 area out to z ~ 1.
Comparison of the stellar populations of bulges and discs using the MaNGA survey
Publisher: Cambridge University Press (CUP)
Date: 2023
DOI: 10.1017/PASA.2022.58
Abstract: We use the MaNGA integral field spectroscopic survey of low-redshift galaxies to compare the stellar populations of the bulge and disc components, identified from their Sérsic profiles, for various s les of galaxies. Bulge-dominated regions tend to be more metal-rich and have slightly older stellar ages than their associated disc-dominated regions. The metallicity difference is consistent with the deeper gravitational potential in bulges relative to discs, which allows bulges to retain more of the metals produced by stars. The age difference is due to star formation persisting longer in discs relative to bulges. Relative to galaxies with lower stellar masses, galaxies with higher stellar masses tend to have bulge-dominated regions that are more metal-rich and older (in light-weighted measurements) than their disc-dominated regions. This suggests high-mass galaxies quench from the inside out, while lower-mass galaxies quench across the whole galaxy simultaneously. Early-type galaxies tend to have bulge-dominated regions the same age as their disc-dominated regions, while late-type galaxies tend to have disc-dominated regions significantly younger than their bulge-dominated regions. Central galaxies tend to have a greater metallicity difference between their bulge-dominated regions and disc-dominated regions than satellite galaxies at similar stellar mass. This difference may be explained by central galaxies being subject to mergers or extended gas accretion bringing new, lower-metallicity gas to the disc, thereby reducing the average metallicity and age of the stars quenching of satellite discs may also play a role.
JWST’s PEARLS: TN J1338–1942 – I. Extreme jet-triggered star formation in a z = 4.11 luminous radio galaxy
Publisher: Oxford University Press (OUP)
Date: 29-04-2023
Abstract: We present the first JWST observations of the z = 4.11 luminous radio galaxy TN J1338–1942, obtained as part of the ‘Prime Extragalactic Areas for Reionization and Lensing Science’ (‘PEARLS’) project. Our NIRCam observations, designed to probe the key rest-frame optical continuum and emission line features at this redshift, enable resolved spectral energy distribution modelling that incorporates both a range of stellar population assumptions and radiative shock models. With an estimated stellar mass of log10(M/M⊙) ∼ 10.9, TN J1338–1942 is confirmed to be one of the most massive galaxies known at this epoch. Our observations also reveal extremely high equivalent-width nebular emission coincident with the luminous AGN jets that is best fit by radiative shocks surrounded by extensive recent star formation. We estimate the total star-formation rate (SFR) could be as high as $\\sim 1600\\, \\text{M}_{\\odot }\\, \\text{yr}^{-1}$ , with the SFR that we attribute to the jet induced burst conservatively $\\gtrsim 500\\, \\text{M}_{\\odot }\\, \\text{yr}^{-1}$ . The mass-weighted age of the star-formation, tmass & 4 Myr, is consistent with the likely age of the jets responsible for the triggered activity and significantly younger than that measured in the core of the host galaxy. The extreme scale of the potential jet-triggered star-formation activity indicates the potential importance of positive AGN feedback in the earliest stages of massive galaxy formation, with our observations also illustrating the extraordinary prospects for detailed studies of high-redshift galaxies with JWST.
Hydra I: An extensible multi-source-finder comparison and cataloguing tool
Publisher: Cambridge University Press (CUP)
Date: 2023
DOI: 10.1017/PASA.2023.24
Abstract: The latest generation of radio surveys are now producing sky survey images containing many millions of radio sources. In this context it is highly desirable to understand the performance of radio image source finder (SF) software and to identify an approach that optimises source detection capabilities. We have created Hydra to be an extensible multi-SF and cataloguing tool that can be used to compare and evaluate different SFs. Hydra, which currently includes the SFs Aegean, Caesar, ProFound, PyBDSF, and Selavy, provides for the addition of new SFs through containerisation and configuration files. The SF input RMS noise and island parameters are optimised to a 90% ‘percentage real detections’ threshold (calculated from the difference between detections in the real and inverted images), to enable comparison between SFs. Hydra provides completeness and reliability diagnostics through observed-deep ( $\\mathcal{D}$ ) and generated-shallow ( $\\mathcal{S}$ ) images, as well as other statistics. In addition, it has a visual inspection tool for comparing residual images through various selection filters, such as S/N bins in completeness or reliability. The tool allows the user to easily compare and evaluate different SFs in order to choose their desired SF, or a combination thereof. This paper is part one of a two part series. In this paper we introduce the Hydra software suite and validate its $\\mathcal{D/S}$ metrics using simulated data. The companion paper demonstrates the utility of Hydra by comparing the performance of SFs using both simulated and real images.
TheugrizYJHKluminosity distributions and densities from the combined MGC, SDSS and UKIDSS LAS data sets
Publisher: Oxford University Press (OUP)
Date: 03-2010
Herschel★-ATLAS/GAMA: a census of dust in optically selected galaxies from stacking at submillimetre wavelengths
Publisher: Oxford University Press (OUP)
Date: 05-03-2012
Herschel-ATLAS/GAMA: How does the far-IR luminosity function depend on galaxy group properties?
Publisher: Oxford University Press (OUP)
Date: 18-06-2014
DOI: 10.1093/MNRAS/STU962
The GALEX-SDSS NUV and FUV flux density and local star formation rate
Publisher: Oxford University Press (OUP)
Date: 17-03-2011
Galaxy And Mass Assembly (GAMA): galaxy environments and star formation rate variations
Publisher: Oxford University Press (OUP)
Date: 06-06-2012
On optical mass estimation methods for galaxy groups
Publisher: Oxford University Press (OUP)
Date: 08-04-2015
DOI: 10.1093/MNRAS/STV463
Architecture of the Andromeda galaxy: A quantitative analysis of clustering in the inner stellar halo
Publisher: Oxford University Press (OUP)
Date: 23-10-2017
Spurious haloes and discreteness-driven relaxation in cosmological simulations
Publisher: Oxford University Press (OUP)
Date: 08-07-2016
Galaxy And Mass Assembly (GAMA): improved cosmic growth measurements using multiple tracers of large-scale structure
Publisher: Oxford University Press (OUP)
Date: 22-10-2013
Fade to grey
Publisher: Oxford University Press (OUP)
Date: 19-11-2020
Abstract: We present a simple model for galaxy attenuation by fitting skirt radiative transfer calculations for ∼10 000 eagle galaxies at redshifts z = 2 − 0. Our model adapts the two-component screen model of Charlot & Fall, parametrizing the optical depth and slope of the interstellar medium screen using the average dust surface density, Σdust. We recover relatively tight relations between these parameters for the eagle s le, but also provide the scatter in these parameters owing to the morphological variation and orientation of galaxies. We also find that these relations are nearly independent of redshift in the eagle model. By pairing our model with an empirical prescription for birth clouds below the resolution scale of the simulation, we reproduce the observed relation between attenuation slope and optical depth for the first time in a cosmological simulation. We demonstrate that this result is remarkably independent of the attenuation properties assumed for the birth cloud screen, merely requiring a boosted attenuation for infant stars. We present this model with a view to interpreting observations, as well as processing semi-analytic models and other hydrodynamic simulations.
Galaxy And Mass Assembly (GAMA): The M-Z relation for galaxy groups
Publisher: Wiley
Date: 05-2013
Abstract: The stellar mass and metallicity are among the fundamental parameters of galaxies. An understanding of the interplay between those properties as well as their environmental dependence will give us a general picture of the physics and feedback processes ongoing in groups of galaxies. We study the relationships and environmental dependencies between the stellar mass, and gas metallicity for more than 1900 galaxies in groups up to redshift 0.35 using the Galaxy And Mass Assembly (GAMA) survey. Using a control s le of more than 28000 star‐forming field galaxies, we find evidence for a decrement of the gas metallicity for galaxies in groups. (© 2013 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
The cosmic radio background from 150 MHz to 8.4 GHz and its division into AGN and star-forming galaxy flux
Publisher: Oxford University Press (OUP)
Date: 16-01-2023
Abstract: We present a revised measurement of the extragalactic background light (EBL) at radio frequencies based on a near complete compendium of radio source counts. We present the radio-EBL at 150 MHz, 325 MHz, 610 MHz, 1.4 GHz, 3 GHz, 5 GHz, and 8.4 GHz. In all cases the contribution to the radio-EBL, per decade of flux, exhibits a two-humped distribution well matched to the active galactic nucleus (AGN) and star-forming galaxy (SFG) populations, and with each population contributing roughly equal energy. Only at 3 GHz are the source count contributions to the EBL fully convergent, and hence we report empirical lower limits to the radio-EBL in the remaining bands. Adopting predictions from the SHARK semi-analytic model for the form of the SFG population, we can fit the fainter source counts providing measurements of the total contribution to the radio-EBL for the SFG and the AGN populations separately. This constitutes an empirically constrained model-dependent measurement for the SFG contribution, but a fully empirical measurement of the AGN contribution. Using the ProSpect spectral energy distribution code we can model the ultraviolet-optical-infrared-mm-radio SFG EBL at all frequencies from the cosmic star-formation history and the adoption of a Chabrier initial mass function. However, significant discrepancy remains (5 ×) between our source-count estimates of the radio-EBL and the direct measurements reported from the Absolute Radiometer for Cosmology, Astrophysics, and Diffuse Emission-2 (ARCADE-2) experiment. We can rule out a significant missing discrete source radio population and suggest that the cause of the high ARCADE-2 radio-EBL values may need to be sought either in the foreground subtraction or as a yet unknown diffuse component in the radio sky.
The Variation of the Gas Content of Galaxy Groups and Pairs Compared to Isolated Galaxies
Publisher: American Astronomical Society
Date: 03-2022
Abstract: We measure how the atomic gas (H i ) fraction f H I = M H I M * of groups and pairs taken as single units vary with average stellar mass (〈 M * 〉) and average star formation rate (〈SFR〉), compared to isolated galaxies. The H i 21 cm emission observation are from (i) archival ALFALFA survey data covering three fields from the GAMA survey (provides environmental and galaxy properties), and (ii) DINGO pilot survey data of one of those fields. The mean f H i for different units (groups airs/isolated galaxies) are measured in regions of the log(〈 M * 〉)–log(〈SFR〉) plane, relative to the z ∼ 0 star-forming main sequence (SFMS) of in idual galaxies, by stacking f H i spectra of in idual units. For ALFALFA, f H i spectra of units are measured by extracting H i spectra over the full groups air areas and iding by the total stellar mass of member galaxies. For DINGO, f H i spectra of units are measured by co-adding H i spectra of in idual member galaxies, followed by ision by their total stellar mass. For all units, the mean f H i decreases as we move to higher 〈 M * 〉 along the SFMS and as we move from above the SFMS to below it at any 〈 M * 〉. From the DINGO-based study, mean f H i in groups appears to be lower compared to isolated galaxies for all 〈 M * 〉 along the SFMS. From the ALFALFA-based study, we find substantially higher mean f H i in groups compared to isolated galaxies (values for pairs being intermediate) for 〈 M * 〉 ≲ 10 9.5 M ⊙ , indicating the presence of substantial amounts of H i not associated with cataloged member galaxies in low mass groups.
Deep extragalactic visible legacy survey (DEVILS): stellar mass growth by morphological type since z = 1
Publisher: Oxford University Press (OUP)
Date: 09-03-2021
Abstract: Using high-resolution Hubble Space Telescope imaging data, we perform a visual morphological classification of ∼36 000 galaxies at z & 1 in the deep extragalactic visible legacy survey/cosmological evolution survey region. As the main goal of this study, we derive the stellar mass function (SMF) and stellar mass density (SMD) sub- ided by morphological types. We find that visual morphological classification using optical imaging is increasingly difficult at z & 1 as the fraction of irregular galaxies and merger systems (when observed at rest-frame UV/blue wavelengths) dramatically increases. We determine that roughly two-thirds of the total stellar mass of the Universe today was in place by z ∼ 1. Double-component galaxies dominate the SMD at all epochs and increase in their contribution to the stellar mass budget to the present day. Elliptical galaxies are the second most dominant morphological type and increase their SMD by ∼2.5 times, while by contrast, the pure-disc population significantly decreases by $\\sim 85{{\\ \\rm per\\ cent}}$. According to the evolution of both high- and low-mass ends of the SMF, we find that mergers and in situ evolution in discs are both present at z & 1, and conclude that double-component galaxies are predominantly being built by the in situ evolution in discs (apparent as the growth of the low-mass end with time), while mergers are likely responsible for the growth of ellipticals (apparent as the increase of intermediate/high-mass end).
Herschel-ATLAS: the surprising diversity of dust-selected galaxies in the local submillimetre Universe
Publisher: Oxford University Press (OUP)
Date: 03-07-2015
Galaxy and Mass Assembly (GAMA): galaxies at the faint end of the Hα luminosity function
Publisher: Oxford University Press (OUP)
Date: 03-2011
Gradual Loss of Social Group Support during Competition Activates Anterior TPJ and Insula but Deactivates Default Mode Network
Publisher: MDPI AG
Date: 25-10-2023
Galaxy quenching time-scales from a forensic reconstruction of their colour evolution
Publisher: Oxford University Press (OUP)
Date: 27-04-2023
Abstract: The time-scales on which galaxies move out of the blue cloud to the red sequence ($\\tau ^{}_\\mathrm{Q}$ ) provide insight into the mechanisms driving quenching. Here, we build upon previous work, where we showcased a method to reconstruct the colour evolution of observed low-redshift galaxies from the Galaxy And Mass Assembly (GAMA) survey based on spectral energy distribution (SED) fitting with ProSpect, together with a statistically driven definition for the blue and red populations. We also use the predicted colour evolution from the shark semi-analytic model, combined with SED fits of our simulated galaxy s le, to study the accuracy of the measured $\\tau ^{}_\\mathrm{Q}$ and gain physical insight into the colour evolution of galaxies. In this work, we measure $\\tau ^{}_\\mathrm{Q}$ in a consistent approach for both observations and simulations. After accounting for selection bias, we find evidence for an increase in $\\tau ^{}_\\mathrm{Q}$ in GAMA as a function of cosmic time (from $\\tau ^{}_\\mathrm{Q}$ ∼ 1 Gyr to $\\tau ^{}_\\mathrm{Q}$ ∼ 2 Gyr in the lapse of ∼4 Gyr), but not in shark ($\\tau ^{}_\\mathrm{Q}$ ≲ 1 Gyr). Our observations and simulations disagree on the effect of stellar mass, with GAMA showing massive galaxies transitioning faster, but is the opposite in shark. We find that environment only impacts galaxies below ∼1010 M⊙ in GAMA, with satellites having shorter $\\tau ^{}_\\mathrm{Q}$ than centrals by ∼0.4 Gyr, with shark only in qualitative agreement. Finally, we compare to previous literature, finding consistency with time-scales in the order of couple Gyr, but with several differences that we discuss.
The SAMI Galaxy Survey: Bulge and Disk Stellar Population Properties in Cluster Galaxies
Publisher: American Astronomical Society
Date: 2021
Abstract: We explore stellar population properties separately in the bulge and the disk of double-component cluster galaxies, to shed light on the formation of lenticular galaxies in dense environments. We study eight low-redshift clusters from the Sydney-AAO Multi-object Integral field Galaxy Survey, using two-dimensional photometric bulge–disk decomposition in the g , r , and i bands to characterize galaxies. For 192 double-component galaxies with M * 10 10 M ⊙ , we estimate the color, age, and metallicity of the bulge and the disk. The analysis of the g − i colors reveals that bulges are redder than their surrounding disks, with a median offset of 0.12 ± 0.02 mag, consistent with previous results. To measure mass-weighted age and metallicity, we investigate three methods: (i) one based on galaxy stellar mass weights for the two components, (ii) one based on flux weights, and (iii) one based on radial separation. The three methods agree in finding 62% of galaxies having bulges that are 2–3 times more metal-rich than the disks. Of the remaining galaxies, 7% have bulges that are more metal-poor than the disks, while for 31%, the bulge and disk metallicities are not significantly different. We observe 23% of galaxies being characterized by bulges older and 34% by bulges younger with respect to the disks. The remaining 43% of galaxies have bulges and disks with statistically indistinguishable ages. Redder bulges tend to be more metal-rich than the disks, suggesting that the redder color in bulges is due to their enhanced metallicity relative to the disks instead of differences in stellar population age.
MegaMorph – multiwavelength measurement of galaxy structure: complete Sérsic profile information from modern surveys
Publisher: Oxford University Press (OUP)
Date: 24-01-2013
DOI: 10.1093/MNRAS/STS633
Are JWST/NIRCam Color Gradients in the Lensed z = 2.3 Dusty Star-forming Galaxy El Anzuelo Due to Central Dust Attenuation or Inside-out Galaxy Growth?
Publisher: American Astronomical Society
Date: 21-09-2023
Herschel-ATLAS/GAMA: a difference between star formation rates in strong-line and weak-line radio galaxies★
Publisher: Oxford University Press (OUP)
Date: 07-01-2013
DOI: 10.1093/MNRAS/STS510
Galaxy And Mass Assembly (GAMA): The Merging Potential of Brightest Group Galaxies
Publisher: American Astronomical Society
Date: 29-10-2021
Hyper-Fit: Fitting Linear Models to Multidimensional Data with Multivariate Gaussian Uncertainties
Publisher: Cambridge University Press (CUP)
Date: 2015
DOI: 10.1017/PASA.2015.33
Abstract: Astronomical data is often uncertain with errors that are heteroscedastic (different for each data point) and covariant between different dimensions. Assuming that a set of D -dimensional data points can be described by a ( D − 1)-dimensional plane with intrinsic scatter, we derive the general likelihood function to be maximised to recover the best fitting model. Alongside the mathematical description, we also release the hyper-fit package for the R statistical language ( sgr/hyper.fit ) and a user-friendly web interface for online fitting ( hyperfit.icrar.org ). The hyper-fit package offers access to a large number of fitting routines, includes visualisation tools, and is fully documented in an extensive user manual. Most of the hyper-fit functionality is accessible via the web interface. In this paper, we include applications to toy ex les and to real astronomical data from the literature: the mass-size, Tully–Fisher, Fundamental Plane, and mass-spin-morphology relations. In most cases, the hyper-fit solutions are in good agreement with published values, but uncover more information regarding the fitted model.
Remnant radio galaxies discovered in a multi-frequency survey
Publisher: Cambridge University Press (CUP)
Date: 2021
DOI: 10.1017/PASA.2020.49
Abstract: The remnant phase of a radio galaxy begins when the jets launched from an active galactic nucleus are switched off. To study the fraction of radio galaxies in a remnant phase, we take advantage of a $8.31$ deg $^2$ subregion of the GAMA 23 field which comprises of surveys covering the frequency range 0.1–9 GHz. We present a s le of 104 radio galaxies compiled from observations conducted by the Murchison Widefield Array (216 MHz), the Australia Square Kilometer Array Pathfinder (887 MHz), and the Australia Telescope Compact Array (5.5 GHz). We adopt an ‘absent radio core’ criterion to identify 10 radio galaxies showing no evidence for an active nucleus. We classify these as new candidate remnant radio galaxies. Seven of these objects still display compact emitting regions within the lobes at 5.5 GHz at this frequency the emission is short-lived, implying a recent jet switch off. On the other hand, only three show evidence of aged lobe plasma by the presence of an ultra-steep-spectrum ( $\\alpha -1.2$ ) and a diffuse, low surface brightness radio morphology. The predominant fraction of young remnants is consistent with a rapid fading during the remnant phase. Within our s le of radio galaxies, our observations constrain the remnant fraction to $4\\%\\lesssim f_{\\mathrm{rem}} \\lesssim 10\\%$ the lower limit comes from the limiting case in which all remnant candidates with hotspots are simply active radio galaxies with faint, undetected radio cores. Finally, we model the synchrotron spectrum arising from a hotspot to show they can persist for 5–10 Myr at 5.5 GHz after the jets switch of—radio emission arising from such hotspots can therefore be expected in an appreciable fraction of genuine remnants.
The new galaxy evolution paradigm revealed by the Herschel surveys
Publisher: Oxford University Press (OUP)
Date: 12-10-2017
ProFit: Bayesian profile fitting of galaxy images
Publisher: Oxford University Press (OUP)
Date: 23-11-2016
TheHerschel-ATLAS Data Release 1 – II. Multi-wavelength counterparts to submillimetre sources
Publisher: Oxford University Press (OUP)
Date: 11-07-2016
Herschel-ATLAS: revealing dust build-up and decline across gas, dust and stellar mass selected samples – I. Scaling relations
Publisher: Oxford University Press (OUP)
Date: 19-10-2016
The near-IR Mbh-L and Mbh-n relations
Publisher: Oxford University Press (OUP)
Date: 22-11-2011
SURFS: Riding the waves with Synthetic UniveRses For Surveys
Publisher: Oxford University Press (OUP)
Date: 10-01-2018
DOI: 10.1093/MNRAS/STY061
Galaxy And Mass Assembly (GAMA): deconstructing bimodality – I. Red ones and blue ones
Publisher: Oxford University Press (OUP)
Date: 26-11-2014
HMFcalc: An online tool for calculating dark matter halo mass functions
Publisher: Elsevier BV
Date: 11-2013
MeerKAT uncovers the physics of an odd radio circle
Publisher: Oxford University Press (OUP)
Date: 24-03-2022
Abstract: Odd radio circles (ORCs) are recently-discovered faint diffuse circles of radio emission, of unknown cause, surrounding galaxies at moderate redshift (z ∼ 0.2 – 0.6). Here, we present detailed new MeerKAT radio images at 1284 MHz of the first ORC, originally discovered with the Australian Square Kilometre Array Pathfinder, with higher resolution (6 arcsec) and sensitivity (∼ 2.4 μJy/beam). In addition to the new images, which reveal a complex internal structure consisting of multiple arcs, we also present polarization and spectral index maps. Based on these new data, we consider potential mechanisms that may generate the ORCs.
Galaxy And Mass Assembly (GAMA): galaxy radial alignments in GAMA groups
Publisher: Oxford University Press (OUP)
Date: 02-07-2013
DOI: 10.1093/MNRAS/STT855
Deep Extragalactic VIsible Legacy Survey (DEVILS): SED fitting in the D10-COSMOS field and the evolution of the stellar mass function and SFR–M⋆ relation
Publisher: Oxford University Press (OUP)
Date: 11-05-2021
Abstract: We present catalogues of stellar masses, star formation rates (SFRs), and ancillary stellar population parameters for galaxies spanning 0 & z & 9 from the Deep Extragalactic VIsible Legacy Survey (DEVILS). DEVILS is a deep spectroscopic redshift survey with very high completeness, covering several premier deep fields including COSMOS (D10). Our stellar mass and SFR estimates are self-consistently derived using the spectral energy distribution (SED) modelling code ProSpect, using well-motivated parametrizations for dust attenuation, star formation histories, and metallicity evolution. We show how these improvements, and especially our physically motivated assumptions about metallicity evolution, have an appreciable systematic effect on the inferred stellar masses, at the level of ∼0.2 dex. To illustrate the scientific value of these data, we map the evolving galaxy stellar mass function (SMF) and the SFR–M⋆ relation for 0 & z & 4.25. In agreement with past studies, we find that most of the evolution in the SMF is driven by the characteristic density parameter, with little evolution in the characteristic mass and low-mass slopes. Where the SFR–M⋆ relation is indistinguishable from a power law at z & 2.6, we see evidence of a bend in the relation at low redshifts (z & 0.45). This suggests evolution in both the normalization and shape of the SFR–M⋆ relation since cosmic noon. It is significant that we only clearly see this bend when combining our new DEVILS measurements with consistently derived values for lower redshift galaxies from the Galaxy And Mass Assembly (GAMA) survey: this shows the power of having consistent treatment for galaxies at all redshifts.
How well do we know the halo mass function?
Publisher: Oxford University Press (OUP)
Date: 10-07-2013
The long and the short of it: the benefits and leverage of ultraviolet-radio galaxy fitting
Publisher: Oxford University Press (OUP)
Date: 05-05-2023
Abstract: Traditionally, the far-ultraviolet (FUV) to far-infrared (FIR) and radio spectral energy distributions (SEDs) of galaxies have been considered separately despite the common physical process shaping them. In this work, we explore the utility of simultaneously fitting FUV-radio SEDs using an extended version of the ProSpect SED fitting code considering contributions from both free–free and synchrotron emission. We use a small s le of galaxies from the Deep Extragalactic VIsible Legacy Survey (DEVILS) and the Key Insights on Nearby Galaxies: a Far-Infrared Survey with Herschel (KINGFISH) where high-quality and robust FUV-radio data are available to provide an ideal s le for testing a radio extension of ProSpect. As the parametrization of the radio extension links the radio continuum to the FIR emission, we explore the benefit of using radio continuum measurements as a constraint on the energy balance between dust attenuation and emission. We find that for situations where mid-IR–FIR photometry is unavailable, including a 1.4 GHz continuum measurement allows for improved accuracy in recovered star formation rates and dust luminosities of galaxies reducing the median uncertainty by 0.1 and 0.2 dex, respectively. We also demonstrate that incorporating 3 and 10 GHz measurements allows for further constraint on the energy balance and therefore the star formation rate and dust luminosity. This demonstrates the advantage of extending FUV–FIR SED fitting techniques to radio frequencies, especially as we move into an era where FIR surveys will remain limited and radio data become abundant (i.e. with the SKA and precursors).
Galaxy and Mass Assembly (GAMA): the GAMA galaxy group catalogue (G3Cv1)
Publisher: Oxford University Press (OUP)
Date: 26-07-2011
Modelling Galaxy Populations in the Era of Big Data
Publisher: Cambridge University Press (CUP)
Date: 05-2014
DOI: 10.1017/S1743921314010710
Abstract: The coming decade will witness a deluge of data from next generation galaxy surveys such as the Square Kilometre Array and Euclid. How can we optimally and robustly analyse these data to maximise scientific returns from these surveys? Here we discuss recent work in developing both the conceptual and software frameworks for carrying out such analyses and their application to the dark matter halo mass function. We summarise what we have learned about the HMF from the last 10 years of precision CMB data using the open-source HMFcalc framework, before discussing how this framework is being extended to the full Halo Model.
Galaxy And Mass Assembly (GAMA): the galaxy luminosity function within the cosmic web
Publisher: Oxford University Press (OUP)
Date: 13-03-2015
DOI: 10.1093/MNRAS/STV237
The causes of the red sequence, the blue cloud, the green valley, and the green mountain
Publisher: Oxford University Press (OUP)
Date: 23-08-2018
Galaxy And Mass Assembly (GAMA): mass–size relations of z < 0.1 galaxies subdivided by Sérsic index, colour and morphology
Publisher: Oxford University Press (OUP)
Date: 10-01-2015
G10/COSMOS: 38 band (far-UV to far-IR) panchromatic photometry using LAMBDAR
Publisher: Oxford University Press (OUP)
Date: 22-09-2017
Deep investigation of neutral gas origins (DINGO): H i stacking experiments with early science data
Publisher: Oxford University Press (OUP)
Date: 26-10-2022
Abstract: We present early science results from Deep Investigation of Neutral Gas Origins (DINGO), an $\\rm H$i survey using the Australian Square Kilometre Array Pathfinder (ASKAP). Using ASKAP subarrays available during its commissioning phase, DINGO early science data were taken over ∼60 deg2 of the Galaxy And Mass Assembly (GAMA) 23 h region with 35.5 h integration time. We make direct detections of six known and one new sources at z & 0.01. Using $\\rm H$ i spectral stacking, we investigate the $\\rm H$ i gas content of galaxies at 0.04 & z & 0.09 for different galaxy colours. The results show that galaxy morphology based on optical colour is strongly linked to $\\rm H$ i gas properties. To examine environmental impacts on the $\\rm H$i gas content of galaxies, three subs les are made based on the GAMA group catalogue. The average $\\rm H$i mass of group central galaxies is larger than those of satellite and isolated galaxies, but with a lower $\\rm H$i gas fraction. We derive a variety of $\\rm H$i scaling relations for physical properties of our s le, including stellar mass, stellar mass surface density, NUV − r colour, specific star formation rate, and halo mass. We find that the derived $\\rm H$i scaling relations are comparable to other published results, with consistent trends also observed to ∼0.5 dex lower limits in stellar mass and stellar surface density. The cosmic $\\rm H$i densities derived from our data are consistent with other published values at similar redshifts. DINGO early science highlights the power of $\\rm H$i spectral stacking techniques with ASKAP.
Galaxy and Mass Assembly (GAMA): the stellar mass budget of galaxy spheroids and discs
Publisher: Oxford University Press (OUP)
Date: 30-07-2016
Galaxy And Mass Assembly (GAMA): trends in galaxy colours, morphology, and stellar populations with large-scale structure, group, and pair environments
Publisher: Oxford University Press (OUP)
Date: 19-06-2015
MIGHTEE-Hi: Evolution of Hi Scaling Relations of Star-forming Galaxies at z < 0.5*
Publisher: American Astronomical Society
Date: 08-2022
Abstract: We present the first measurements of H i galaxy scaling relations from a blind survey at z 0.15. We perform spectral stacking of 9023 spectra of star-forming galaxies undetected in H i at 0.23 z 0.49, extracted from MIGHTEE-H i Early Science data cubes, acquired with the MeerKAT radio telescope. We stack galaxies in bins of galaxy properties (stellar mass M * , star formation rateSFR, and specific star formation rate sSFR, with sSFR ≡ M * /SFR), obtaining ≳5 σ detections in most cases, the strongest H i -stacking detections to date in this redshift range. With these detections, we are able to measure scaling relations in the probed redshift interval, finding evidence for a moderate evolution from the median redshift of our s le z med ∼ 0.37 to z ∼ 0. In particular, low- M * galaxies ( log 10 ( M * / M ⊙ ) ∼ 9 ) experience a strong H i depletion (∼0.5 dex in log 10 ( M H I / M ⊙ ) ), while massive galaxies ( log 10 ( M * / M ⊙ ) ∼ 11 ) keep their H i mass nearly unchanged. When looking at the star formation activity, highly star-forming galaxies evolve significantly in M H I ( f H I , where f H I ≡ M H I / M * ) at fixed SFR (sSFR), while at the lowest probed SFR (sSFR) the scaling relations show no evolution. These findings suggest a scenario in which low- M * galaxies have experienced a strong H i depletion during the last ∼5 Gyr, while massive galaxies have undergone a significant H i replenishment through some accretion mechanism, possibly minor mergers. Interestingly, our results are in good agreement with the predictions of the simba simulation. We conclude that this work sets novel important observational constraints on galaxy scaling relations.
Self-consistent Bulge/Disk/Halo Galaxy Dynamical Modeling Using Integral Field Kinematics
Publisher: American Astronomical Society
Date: 17-11-2017
Galaxy and Mass Assembly (GAMA): probing the merger histories of massive galaxies via stellar populations
Publisher: Oxford University Press (OUP)
Date: 28-02-2017
DOI: 10.1093/MNRAS/STX503
Galaxy and Mass Assembly: the evolution of bias in the radio source population to z∼1.5
Publisher: Oxford University Press (OUP)
Date: 22-03-2014
DOI: 10.1093/MNRAS/STU354
Galaxy And Mass Assembly (GAMA): The group H i mass as a function of halo mass
Publisher: Oxford University Press (OUP)
Date: 26-05-2023
Abstract: We determine the atomic hydrogen (H i) to halo mass relation (HIHM) using Arecibo Legacy Fast ALFA survey H i data at the location of optically selected groups from the Galaxy And Mass Assembly (GAMA) survey. We make direct H i detections for 37 GAMA groups. Using H i group spectral stacking of 345 groups, we study the group H i content as a function of halo mass across a halo mass range of 1011–1014.7 M⊙. We also correct our results for Eddington bias. We find that the group H i mass generally rises as a function of halo mass from 1.3% of the halo mass at $10^{11.6} \\, \\text{M}_\\odot$ to 0.4% at $10^{13.7} \\, \\text{M}_\\odot$ with some indication of flattening towards the high-mass end. Despite the differences in optical survey limits, group catalogues, and halo mass estimation methods, our results are consistent with previous group H i-stacking studies. Our results are also consistent with mock observations from shark and IllustrisTNG.
Galaxy and Mass Assembly (GAMA): Optimal Tiling of Dense Surveys with a Multi-Object Spectrograph
Publisher: Cambridge University Press (CUP)
Date: 2010
DOI: 10.1071/AS09053
Abstract: A heuristic greedy algorithm is developed for efficiently tiling spatially dense redshift surveys. In its first application to the Galaxy and MassAssembly (GAMA) redshift survey we find it rapidly improves the spatial uniformity of our data, and naturally corrects for any spatial bias introduced by the 2dF multi-object spectrograph. We make conservative predictions for the final state of the GAMA redshift survey after our final allocation of time, and can be confident that even if worse than typical weather affects our observations, all of our main survey requirements will be met.
Deep Extragalactic VIsible Legacy Survey (DEVILS): evolution of the σSFR–M⋆ relation and implications for self-regulated star formation
Publisher: Oxford University Press (OUP)
Date: 09-11-2021
Abstract: We present the evolution of the star formation dispersion–stellar mass relation (σSFR–M⋆) in the DEVILS D10 region using new measurements derived using the ProSpect spectral energy distribution fitting code. We find that σSFR–M⋆ shows the characteristic ‘U-shape’ at intermediate stellar masses from 0.1 & z & 0.7 for a number of metrics, including using the deconvolved intrinsic dispersion. A physical interpretation of this relation is the combination of stochastic star formation and stellar feedback causing large scatter at low stellar masses and AGN feedback causing asymmetric scatter at high stellar masses. As such, the shape of this distribution and its evolution encodes detailed information about the astrophysical processes affecting star formation, feedback and the lifecycle of galaxies. We find that the stellar mass that the minimum σSFR occurs evolves linearly with redshift, moving to higher stellar masses with increasing lookback time and traces the turnover in the star-forming sequence. This minimum σSFR point is also found to occur at a fixed specific star formation rate (sSFR) at all epochs (sSFR ∼ 10−9.6 Gyr−1). The physical interpretation of this is that there exists a maximum sSFR at which galaxies can internally self-regulate on the tight sequence of star formation. At higher sSFRs, stochastic stellar processes begin to cause galaxies to be pushed both above and below the star-forming sequence leading to increased SFR dispersion. As the Universe evolves, a higher fraction of galaxies will drop below this sSFR threshold, causing the dispersion of the low stellar mass end of the star-forming sequence to decrease with time.
GAMA/H-ATLAS: the local dust mass function and cosmic density as a function of galaxy type – a benchmark for models of galaxy evolution
Publisher: Oxford University Press (OUP)
Date: 05-06-2018
Abstract: We present the dust mass function (DMF) of 15 750 galaxies with redshift $z$ & 0.1, drawn from the overlapping area of the GAMA and H-ATLAS surveys. The DMF is derived using the density corrected Vmax method, where we estimate Vmax using: (i) the normal photometric selection limit (pVmax) and (ii) a bivariate brightness distribution (BBD) technique, which accounts for two selection effects. We fit the data with a Schechter function, and find $M^{*}=(4.65 \\pm 0.18)\\times 10^{7}\\,h^2_{70}\\, \\mathrm{ M}_{\\odot }$, α = (−1.22 ± 0.01), $\\phi ^{*}=(6.26 \\pm 0.28)\\times 10^{-3}\\,h^3_{70}\\,\\rm Mpc^{-3}\\,dex^{-1}$. The resulting dust mass density parameter integrated down to 104 M⊙ is Ωd = (1.11 ± 0.02) × 10−6 which implies the mass fraction of baryons in dust is $f_{m_\\mathrm{ b}}=(2.40\\pm 0.04)\\times 10^{-5}$ cosmic variance adds an extra 7–17 per cent uncertainty to the quoted statistical errors. Our measurements have fewer galaxies with high dust mass than predicted by semi-analytic models. This is because the models include too much dust in high stellar mass galaxies. Conversely, our measurements find more galaxies with high dust mass than predicted by hydrodynamical cosmological simulations. This is likely to be from the long time-scales for grain growth assumed in the models. We calculate DMFs split by galaxy type and find dust mass densities of Ωd = (0.88 ± 0.03) × 10−6 and Ωd = (0.060 ± 0.005) × 10−6 for late types and early types, respectively. Comparing to the equivalent galaxy stellar mass functions (GSMF) we find that the DMF for late types is well matched by the GSMF scaled by (8.07 ± 0.35) × 10−4.
Star-forming, rotating spheroidal galaxies in the GAMA and SAMI surveys
Publisher: Oxford University Press (OUP)
Date: 12-08-2019
Abstract: The Galaxy And Mass Assembly (GAMA) survey has morphologically identified a class of ‘Little Blue Spheroid’ (LBS) galaxies whose relationship to other classes of galaxies we now examine in detail. Considering a s le of 868 LBSs, we find that such galaxies display similar but not identical colours, specific star formation rates, stellar population ages, mass-to-light ratios, and metallicities to Sd-Irr galaxies. We also find that LBSs typically occupy environments of even lower density than those of Sd-Irr galaxies, where ∼65 per cent of LBS galaxies live in isolation. Using deep, high-resolution imaging from VST KiDS and the new Bayesian, 2D galaxy profile modelling code profit, we further examine the detailed structure of LBSs and find that their Sérsic indices, sizes, and axial ratios are compatible with those of low-mass elliptical galaxies. We then examine SAMI Galaxy survey integral field emission line kinematics for a subset of 62 LBSs and find that the majority (42) of these galaxies display ordered rotation with the remainder displaying disturbed/non-ordered dynamics. Finally, we consider potential evolutionary scenarios for a population with this unusual combination of properties, concluding that LBSs are likely formed by a mixture of merger and accretion processes still recently active in low-redshift dwarf populations. We also infer that if LBS-like galaxies were subjected to quenching in a rich environment, they would plausibly resemble cluster dwarf ellipticals.
Galaxy And Mass Assembly (GAMA): spectroscopic analysis
Publisher: Oxford University Press (OUP)
Date: 07-02-2013
DOI: 10.1093/MNRAS/STT030
Recovering λR and V/σ from seeing-dominated IFS data
Publisher: Oxford University Press (OUP)
Date: 27-06-2020
Abstract: Observers experience a series of limitations when measuring galaxy kinematics, such as variable seeing conditions and aperture size. These effects can be reduced using empirical corrections, but these equations are usually applicable within a restrictive set of boundary conditions (e.g. Sérsic indices within a given range) that can lead to biases when trying to compare measurements made across a full kinematic survey. In this work, we present new corrections for two widely used kinematic parameters, λR and V/σ, that are applicable across a broad range of galaxy shapes, measurement radii, and ellipticities. We take a series of mock observations of N-body galaxy models and use these to quantify the relationship between the observed kinematic parameters, structural properties, and different seeing conditions. Derived corrections are then tested using the full catalogue of galaxies, including hydrodynamic models from the eagle simulation. Our correction is most effective for regularly rotating systems, yet the kinematic parameters of all galaxies – fast, slow, and irregularly rotating systems – are recovered successfully. We find that λR is more easily corrected than V/σ, with relative deviations of 0.02 and 0.06 dex, respectively. The relationship between λR and V/σ, as described by the parameter κ, also has a minor dependence on seeing conditions. These corrections will be particularly useful for stellar kinematic measurements in current and future integral field spectroscopic surveys of galaxies.
Extracting galaxy merger timescales I: Tracking haloes with WhereWolf and spinning orbits with OrbWeaver
Publisher: Oxford University Press (OUP)
Date: 18-11-2019
Abstract: Hierarchical models of structure formation predict that dark matter halo assembly histories are characterised by episodic mergers and interactions with other haloes. An accurate description of this process will provide insights into the dynamical evolution of haloes and the galaxies that reside in them. Using large cosmological N-body simulations, we characterise halo orbits to study the interactions between substructure haloes and their hosts, and how different evolutionary histories map to different classes of orbits. We use two new software tools - WhereWolf, which uses halo group catalogues and merger trees to ensure that haloes are tracked accurately in dense environments, and OrbWeaver, which quantifies each halo’s orbital parameters. We demonstrate how WhereWolf improves the accuracy of halo merger trees, and we use OrbWeaver to quantify orbits of haloes. We assess how well analytical prescriptions for the merger timescale from the literature compare to measured merger timescales from our simulations and find that existing prescriptions perform well, provided the ratio of substructure-to-host mass is not too small. In the limit of small substructure-to-host mass ratio, we find that the prescriptions can overestimate the merger timescales substantially, such that haloes are predicted to survive well beyond the end of the simulation. This work highlights the need for a revised analytical prescription for the merger timescale that more accurately accounts for processes such as catastrophic tidal disruption.
Galaxy And Mass Assembly (GAMA): estimating galaxy group masses via caustic analysis
Publisher: Oxford University Press (OUP)
Date: 07-05-2012
xGASS
Publisher: Oxford University Press (OUP)
Date: 17-03-2020
Abstract: We use our catalogue of structural decomposition measurements for the extended GALEX Arecibo SDSS Survey (xGASS) to study the role of bulges both along and across the galaxy star-forming main sequence (SFMS). We show that the slope in the sSFR–M⋆ relation flattens by ∼0.1 dex per decade in M⋆ when re-normalizing specifice star formation rate (sSFR) by disc stellar mass instead of total stellar mass. However, recasting the sSFR–M⋆ relation into the framework of only disc-specific quantities shows that a residual trend remains against disc stellar mass with equivalent slope and comparable scatter to that of the total galaxy relation. This suggests that the residual declining slope of the SFMS is intrinsic to the disc components of galaxies. We further investigate the distribution of bulge-to-total ratios (B/T) as a function of distance from the SFMS (ΔSFRMS). At all stellar masses, the average B/T of local galaxies decreases monotonically with increasing ΔSFRMS. Contrary to previous works, we find that the upper envelope of the SFMS is not dominated by objects with a significant bulge component. This rules out a scenario in which, in the local Universe, objects with increased star formation activity are simultaneously experiencing a significant bulge growth. We suggest that much of the discrepancies between different works studying the role of bulges originate from differences in the methodology of structurally decomposing galaxies.
JWST's PEARLS: Mothra, a new kaiju star at z=2.091 extremely magnified by MACS0416, and implications for dark matter models
Publisher: EDP Sciences
Date: 19-09-2023
Euclid preparation
Publisher: EDP Sciences
Date: 03-2023
DOI: 10.1051/0004-6361/202245042
Abstract: The various Euclid imaging surveys will become a reference for studies of galaxy morphology by delivering imaging over an unprecedented area of 15 000 square degrees with high spatial resolution. In order to understand the capabilities of measuring morphologies from Euclid -detected galaxies and to help implement measurements in the pipeline of the Organisational Unit MER of the Euclid Science Ground Segment, we have conducted the Euclid Morphology Challenge, which we present in two papers. While the companion paper focusses on the analysis of photometry, this paper assesses the accuracy of the parametric galaxy morphology measurements in imaging predicted from within the Euclid Wide Survey. We evaluate the performance of five state-of-the-art surface-brightness-fitting codes, DeepLeGATo , Galapagos-2 , Morfometryka , ProFit and SourceXtractor++ , on a s le of about 1.5 million simulated galaxies (350 000 above 5 σ ) resembling reduced observations with the Euclid VIS and NIR instruments. The simulations include analytic Sérsic profiles with one and two components, as well as more realistic galaxies generated with neural networks. We find that, despite some code-specific differences, all methods tend to achieve reliable structural measurements ( 10% scatter on ideal Sérsic simulations) down to an apparent magnitude of about I E = 23 in one component and I E = 21 in two components, which correspond to a signal-to-noise ratio of approximately 1 and 5, respectively. We also show that when tested on non-analytic profiles, the results are typically degraded by a factor of 3, driven by systematics. We conclude that the official Euclid Data Releases will deliver robust structural parameters for at least 400 million galaxies in the Euclid Wide Survey by the end of the mission. We find that a key factor for explaining the different behaviour of the codes at the faint end is the set of adopted priors for the various structural parameters.
Galaxy And Mass Assembly (GAMA): the life and times of L★ galaxies
Publisher: Oxford University Press (OUP)
Date: 08-03-2013
DOI: 10.1093/MNRAS/STT156
Galaxy And Mass Assembly (GAMA): the absence of stellar mass segregation in galaxy groups and consistent predictions from GALFORM and EAGLE simulations
Publisher: Oxford University Press (OUP)
Date: 12-09-2016
GALAXY AND MASS ASSEMBLY (GAMA): WITNESSING THE ASSEMBLY OF THE CLUSTER ABELL 1882
Publisher: American Astronomical Society
Date: 11-07-2013
Euclid preparation
Publisher: EDP Sciences
Date: 03-2023
DOI: 10.1051/0004-6361/202245041
Abstract: The European Space Agency's Euclid mission will provide high-quality imaging for about 1.5 billion galaxies. A software pipeline to automatically process and analyse such a huge amount of data in real time is being developed by the Science Ground Segment of the Euclid Consortium this pipeline will include a model-fitting algorithm, which will provide photometric and morphological estimates of paramount importance for the core science goals of the mission and for legacy science. The Euclid Morphology Challenge is a comparative investigation of the performance of five model-fitting software packages on simulated Euclid data, aimed at providing the baseline to identify the best-suited algorithm to be implemented in the pipeline. In this paper we describe the simulated dataset, and we discuss the photometry results. A companion paper is focussed on the structural and morphological estimates. We created mock Euclid images simulating five fields of view of 0.48 deg 2 each in the I E band of the VIS instrument, containing a total of about one and a half million galaxies (of which 350 000 have a nominal signal-to-noise ratio above 5), each with three realisations of galaxy profiles (single and double Sérsic, and 'realistic' profiles obtained with a neural network) for one of the fields in the double Sérsic realisation, we also simulated images for the three near-infrared Y E , J E , and H E bands of the NISP-P instrument, and five Rubin/LSST optical complementary bands ( u , g, r, i, and z ), which together form a typical dataset for an Euclid observation. The images were simulated at the expected Euclid Wide Survey depths. To analyse the results, we created diagnostic plots and defined metrics to take into account the completeness of the provided catalogues, as well as the median biases, dispersions, and outlier fractions of their measured flux distributions. Five model-fitting software packages ( DeepLeGATo , Galapagos-2 , Morfometryka , ProFit , and SourceXtractor++ ) were compared, all typically providing good results. Of the differences among them, some were at least partly due to the distinct strategies adopted to perform the measurements. In the best-case scenario, the median bias of the measured fluxes in the analytical profile realisations is below 1% at a signal-to-noise ratio above 5 in I E , and above 10 in all the other bands the dispersion of the distribution is typically comparable to the theoretically expected one, with a small fraction of catastrophic outliers. However, we can expect that real observations will prove to be more demanding, since the results were found to be less accurate for the most realistic realisation. We conclude that existing model-fitting software can provide accurate photometric measurements on Euclid datasets. The results of the challenge are fully available and reproducible through an online plotting tool.
Shark: introducing an open source, free, and flexible semi-analytic model of galaxy formation
Publisher: Oxford University Press (OUP)
Date: 06-09-2018
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University Of Bristol
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