ORCID Profile
0000-0003-0247-1204
Current Organisation
University of New South Wales
Does something not look right? The information on this page has been harvested from data sources that may not be up to date. We continue to work with information providers to improve coverage and quality. To report an issue, use the Feedback Form.
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.
Astronomical and Space Sciences | Cosmology and Extragalactic Astronomy |
Expanding Knowledge in the Physical Sciences | Expanding Knowledge in the Information and Computing Sciences
Publisher: Oxford University Press (OUP)
Date: 26-02-2014
DOI: 10.1093/MNRAS/STU095
Publisher: Oxford University Press (OUP)
Date: 22-02-2017
DOI: 10.1093/MNRAS/STX441
Publisher: Oxford University Press (OUP)
Date: 08-03-2017
DOI: 10.1093/MNRAS/STX562
Publisher: American Astronomical Society
Date: 20-01-2017
Publisher: EDP Sciences
Date: 31-10-2012
Publisher: Springer Science and Business Media LLC
Date: 23-04-2018
Publisher: Cambridge University Press (CUP)
Date: 2021
DOI: 10.1017/PASA.2021.25
Abstract: We present an overview of the M iddle A ges G alaxy P roperties with I ntegral Field Spectroscopy (MAGPI) survey, a Large Program on the European Southern Observatory Very Large Telescope. MAGPI is designed to study the physical drivers of galaxy transformation at a lookback time of 3–4 Gyr, during which the dynamical, morphological, and chemical properties of galaxies are predicted to evolve significantly. The survey uses new medium-deep adaptive optics aided Multi-Unit Spectroscopic Explorer (MUSE) observations of fields selected from the Galaxy and Mass Assembly (GAMA) survey, providing a wealth of publicly available ancillary multi-wavelength data. With these data, MAGPI will map the kinematic and chemical properties of stars and ionised gas for a s le of 60 massive ( ${ }7 \\times 10^{10} {\\mathrm{M}}_\\odot$ ) central galaxies at $0.25 z .35$ in a representative range of environments (isolated, groups and clusters). The spatial resolution delivered by MUSE with Ground Layer Adaptive Optics ( $0.6-0.8$ arcsec FWHM) will facilitate a direct comparison with Integral Field Spectroscopy surveys of the nearby Universe, such as SAMI and MaNGA, and at higher redshifts using adaptive optics, for ex le, SINS. In addition to the primary (central) galaxy s le, MAGPI will deliver resolved and unresolved spectra for as many as 150 satellite galaxies at $0.25 z .35$ , as well as hundreds of emission-line sources at $z 6$ . This paper outlines the science goals, survey design, and observing strategy of MAGPI. We also present a first look at the MAGPI data, and the theoretical framework to which MAGPI data will be compared using the current generation of cosmological hydrodynamical simulations including EAGLE , Magneticum , HORIZON-AGN , and Illustris-TNG . Our results show that cosmological hydrodynamical simulations make discrepant predictions in the spatially resolved properties of galaxies at $z\\approx 0.3$ . MAGPI observations will place new constraints and allow for tangible improvements in galaxy formation theory.
Publisher: Oxford University Press (OUP)
Date: 04-02-2014
Publisher: Oxford University Press (OUP)
Date: 09-07-2013
Publisher: Oxford University Press (OUP)
Date: 11-09-2013
Publisher: Oxford University Press (OUP)
Date: 14-05-2020
Abstract: We investigate the stellar kinematics of the bulge and disk components in 826 galaxies with a wide range of morphology from the Sydney-AAO Multi-object Integral-field spectroscopy Galaxy Survey. The spatially resolved rotation velocity (V) and velocity dispersion (σ) of bulge and disk components have been simultaneously estimated using the penalized pixel fitting (ppxf) method with photometrically defined weights for the two components. We introduce a new subroutine of ppxf for dealing with degeneracy in the solutions. We show that the V and σ distributions in each galaxy can be reconstructed using the kinematics and weights of the bulge and disk components. The combination of two distinct components provides a consistent description of the major kinematic features of galaxies over a wide range of morphological types. We present Tully–Fisher and Faber–Jackson relations showing that the galaxy stellar mass scales with both V and σ for both components of all galaxy types. We find a tight Faber–Jackson relation even for the disk component. We show that the bulge and disk components are kinematically distinct: (1) the two components show scaling relations with similar slopes, but different intercepts (2) the spin parameter λR indicates bulges are pressure-dominated systems and disks are supported by rotation and (3) the bulge and disk components have, respectively, low and high values in intrinsic ellipticity. Our findings suggest that the relative contributions of the two components explain, at least to first order, the complex kinematic behaviour of galaxies.
Publisher: Oxford University Press (OUP)
Date: 02-2016
Publisher: Oxford University Press (OUP)
Date: 03-05-2017
Publisher: American Astronomical Society
Date: 19-06-2009
Publisher: Oxford University Press (OUP)
Date: 11-2021
Abstract: We use a s le of z = 0 galaxies visually classified as slow rotators (SRs) in the eagle hydrodynamical simulations to explore the effect of galaxy mergers on their formation, characterize their intrinsic galaxy properties, and study the connection between quenching and kinematic transformation. SRs that have had major or minor mergers (mass ratios ≥0.3 and 0.1−0.3, respectively) tend to have a higher triaxiality parameter and ex-situ stellar fractions than those that had exclusively very minor mergers or formed in the absence of mergers (‘no-merger’ SRs). No-merger SRs are more compact, have lower black hole-to-stellar mass ratios and quenched later than other SRs, leaving imprints on their z = 0 chemical composition. For the vast majority of SRs we find that quenching, driven by active galactic nuclei feedback, precedes kinematic transformation, except for satellite SRs, in which these processes happen in tandem. However, in ≈50 per cent of these satellites, satellite–satellite mergers are responsible for their SR fate, while environment (i.e. tidal field and interactions with the central) can account for the transformation in the rest. By splitting SRs into kinematic sub-classes, we find that flat SRs prefer major mergers round SRs prefer minor or very minor mergers prolate SRs prefer gas-poor mergers. Flat and prolate SRs are more common among satellites hosted by massive haloes ($\\gt 10^{13.6}\\, \\rm M_{\\odot }$) and centrals of high masses ($M_{\\star } \\gt 10^{10.5}\\, \\rm M_{\\odot }$). Although eagle galaxies display kinematic properties that broadly agree with observations, there are areas of disagreement, such as inverted stellar age and velocity dispersion profiles. We discuss these and how upcoming simulations can solve them.
Publisher: Oxford University Press (OUP)
Date: 22-06-2018
Publisher: Oxford University Press (OUP)
Date: 26-09-2019
Publisher: American Astronomical Society
Date: 11-03-2010
Publisher: Oxford University Press (OUP)
Date: 10-06-2014
DOI: 10.1093/MNRAS/STU937
Publisher: Oxford University Press (OUP)
Date: 03-2011
Publisher: Oxford University Press (OUP)
Date: 20-11-2015
Publisher: Oxford University Press (OUP)
Date: 02-08-2018
Publisher: Oxford University Press (OUP)
Date: 02-05-2023
Abstract: We investigate the impact of environment on the internal mass distribution of galaxies using the Middle Ages Galaxy Properties with Integral field spectroscopy (MAGPI) survey. We use 2D resolved stellar kinematics to construct Jeans dynamical models for galaxies at mean redshift z ∼ 0.3, corresponding to a lookback time of 3–4 Gyr. The internal mass distribution for each galaxy is parametrized by the combined mass density slope γ (baryons + dark matter), which is the logarithmic change of density with radius. We use a MAGPI s le of 28 galaxies from low-to-mid density environments and compare to density slopes derived from galaxies in the high density Frontier Fields clusters in the redshift range 0.29 & z & 0.55, corresponding to a lookback time of ∼5 Gyr. We find a median density slope of γ = −2.22 ± 0.05 for the MAGPI s le, which is significantly steeper than the Frontier Fields median slope (γ = −2.00 ± 0.04), implying the cluster galaxies are less centrally concentrated in their mass distribution than MAGPI galaxies. We also compare to the distribution of density slopes from galaxies in ATLAS3D at z ∼ 0, because the s le probes a similar environmental range as MAGPI. The ATLAS3D median total slope is γ = −2.25 ± 0.02, consistent with the MAGPI median. Our results indicate environment plays a role in the internal mass distribution of galaxies, with no evolution of the slope in the last 3–4 Gyr. These results are in agreement with the predictions of cosmological simulations.
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.
Publisher: Oxford University Press (OUP)
Date: 11-11-2014
Publisher: Oxford University Press (OUP)
Date: 13-01-2015
Publisher: American Astronomical Society
Date: 05-03-2019
Publisher: Oxford University Press (OUP)
Date: 29-06-2013
DOI: 10.1093/MNRAS/STT890
Publisher: Oxford University Press (OUP)
Date: 08-03-2019
DOI: 10.1093/MNRAS/STZ670
Abstract: We present a novel Bayesian method, referred to as blobby3d, to infer gas kinematics that mitigates the effects of beam smearing for observations using integral field spectroscopy. The method is robust for regularly rotating galaxies despite substructure in the gas distribution. Modelling the gas substructure within the disc is achieved by using a hierarchical Gaussian mixture model. To account for beam smearing effects, we construct a modelled cube that is then convolved per wavelength slice by the seeing, before calculating the likelihood function. We show that our method can model complex gas substructure including clumps and spiral arms. We also show that kinematic asymmetries can be observed after beam smearing for regularly rotating galaxies with asymmetries only introduced in the spatial distribution of the gas. We present findings for our method applied to a s le of 20 star-forming galaxies from the SAMI Galaxy Survey. We estimate the global H α gas velocity dispersion for our s le to be in the range $\\bar{\\sigma }_v \\sim$[7, 30] km s−1. The relative difference between our approach and estimates using the single Gaussian component fits per spaxel is $\\Delta \\bar{\\sigma }_v / \\bar{\\sigma }_v = - 0.29 \\pm 0.18$ for the H α flux-weighted mean velocity dispersion.
Publisher: Oxford University Press (OUP)
Date: 26-05-2021
Abstract: Large galaxy s les from multiobject integral field spectroscopic (IFS) surveys now allow for a statistical analysis of the z ∼ 0 galaxy population using resolved kinematic measurements. However, the improvement in number statistics comes at a cost, with multiobject IFS survey more severely impacted by the effect of seeing and lower signal-to-noise ratio. We present an analysis of ∼1800 galaxies from the SAMI Galaxy Survey taking into account these effects. We investigate the spread and overlap in the kinematic distributions of the spin parameter proxy $\\lambda _{R_{\\rm {e}}}$ as a function of stellar mass and ellipticity εe. For SAMI data, the distributions of galaxies identified as regular and non-regular rotators with kinemetry show considerable overlap in the $\\lambda _{R_{\\rm {e}}}$–εe diagram. In contrast, visually classified galaxies (obvious and non-obvious rotators) are better separated in $\\lambda _{R_{\\rm {e}}}$ space, with less overlap of both distributions. Then, we use a Bayesian mixture model to analyse the observed $\\lambda _{R_{\\rm {e}}}$–log (M⋆/M⊙) distribution. By allowing the mixture probability to vary as a function of mass, we investigate whether the data are best fit with a single kinematic distribution or with two. Below log (M⋆/M⊙) ∼ 10.5, a single beta distribution is sufficient to fit the complete $\\lambda _{R_{\\rm {e}}}$ distribution, whereas a second beta distribution is required above log (M⋆/M⊙) ∼ 10.5 to account for a population of low-$\\lambda _{R_{\\rm {e}}}$ galaxies. While the Bayesian mixture model presents the cleanest separation of the two kinematic populations, we find the unique information provided by visual classification of galaxy kinematic maps should not be disregarded in future studies. Applied to mock-observations from different cosmological simulations, the mixture model also predicts bimodal $\\lambda _{R_{\\rm {e}}}$ distributions, albeit with different positions of the $\\lambda _{R_{\\rm {e}}}$ peaks. Our analysis validates the conclusions from previous, smaller IFS surveys, but also demonstrates the importance of using selection criteria for identifying different kinematic classes that are dictated by the quality and resolution of the observed or simulated data.
Publisher: Oxford University Press (OUP)
Date: 04-08-2016
Publisher: Oxford University Press (OUP)
Date: 16-06-2011
Publisher: Oxford University Press (OUP)
Date: 13-04-2011
Publisher: Oxford University Press (OUP)
Date: 08-03-2011
Publisher: Oxford University Press (OUP)
Date: 26-11-2014
Publisher: Oxford University Press (OUP)
Date: 15-02-2023
Abstract: We explore local and global dynamical differences between the kinematics of ionized gas and stars in a s le of galaxies from Data Release 3 of the SAMI Galaxy Survey. We find better agreement between local (i.e. comparing on a spaxel-to-spaxel basis) velocities and dispersion of gas and stars in younger systems as with previous work on the asymmetric drift in galaxies, suggesting that the dynamics of stars and ionized gas are initially coupled. The intrinsic scatter around the velocity and dispersion relations increases with increasing stellar age and mass, suggesting that subsequent mechanisms, such as internal processes, ergent star formation, and assembly histories, also play a role in setting and altering the dynamics of galaxies. The global (flux-weighted) dynamical support of older galaxies is hotter than in younger systems. We find that the ionized gas in galaxies is almost always dynamically colder than the stars with a steeper velocity gradient. In absolute terms, the local difference in velocity dispersion is more pronounced than the local difference in velocity, possibly reflecting inherent differences in the impact of turbulence, inflow and/or feedback on gas compared to stars. We suggest how these findings may be taken into account when comparing high and low redshift galaxy s les to infer dynamical evolution.
Publisher: Oxford University Press (OUP)
Date: 07-06-2019
Publisher: Oxford University Press (OUP)
Date: 09-10-2012
Publisher: Oxford University Press (OUP)
Date: 24-11-2017
Publisher: Oxford University Press (OUP)
Date: 26-05-2021
Abstract: We use comparisons between the Sydney-AAO Multi-object Integral Field Spectrograph (SAMI) Galaxy Survey and equilibrium galaxy models to infer the importance of disc fading in the transition of spirals into lenticular (S0) galaxies. The local S0 population has both higher photometric concentration and lower stellar spin than spiral galaxies of comparable mass and we test whether this separation can be accounted for by passive aging alone. We construct a suite of dynamically self-consistent galaxy models, with a bulge, disc, and halo using the galactics code. The dispersion-dominated bulge is given a uniformly old stellar population, while the disc is given a current star formation rate putting it on the main sequence, followed by sudden instantaneous quenching. We then generate mock observables (r-band images, stellar velocity, and dispersion maps) as a function of time since quenching for a range of bulge/total (B/T) mass ratios. The disc fading leads to a decline in measured spin as the bulge contribution becomes more dominant, and also leads to increased concentration. However, the quantitative changes observed after 5 Gyr of disc fading cannot account for all of the observed difference. We see similar results if we instead sub ide our SAMI Galaxy Survey s le by star formation (relative to the main sequence). We use EAGLE simulations to also take into account progenitor bias, using size evolution to infer quenching time. The EAGLE simulations suggest that the progenitors of current passive galaxies typically have slightly higher spin than present day star-forming disc galaxies of the same mass. As a result, progenitor bias moves the data further from the disc fading model scenario, implying that intrinsic dynamical evolution must be important in the transition from star-forming discs to passive discs.
Publisher: Oxford University Press (OUP)
Date: 21-12-2009
Publisher: Oxford University Press (OUP)
Date: 21-03-2022
Abstract: We present results from MUSE observations of a 21-cm ${\\rm H\\, {\\small I}}$ absorption system detected with the Australian Square Kilometre Array Pathfinder radio telescope at redshift z = 0.4503 towards the z = 1.71 quasar PKS 1610-771. We identify four galaxies (A, B, X, and Y) at the same redshift as the 21-cm ${\\rm H\\, {\\small I}}$ D ed Lyman-α (DLA) absorption system, with impact parameters ranging from less than 10 kpc to almost 200 kpc from the quasar sightline. ${\\rm Ca\\, {\\small II}}$ and ${\\rm Na\\, {\\small I}}$ absorption is seen in the MUSE spectrum of the background QSO, with velocities coinciding with the initial ${\\rm H\\, {\\small I}}$ 21-cm detection, but tracing less dense and warmer gas. This metal-line component aligns with the rotating ionized disc of galaxy B (impact parameter 18 kpc from the QSO) and appears to be corotating with the galaxy disc. In contrast, the 21-cm ${\\rm H\\, {\\small I}}$ absorber is blueshifted relative to the galaxies nearest the absorber and has the opposite sign to the velocity field of galaxy B. Since galaxies A and B are separated by only 17 kpc on the sky and 70 km s−1 in velocity, it appears likely that the 21-cm detection traces extragalactic clouds of gas formed from their interaction. This system reveals that the cold 100 K neutral gas critical for star formation can be associated with complex structures beyond the galaxy disc, and is a first case study made in preparation for future large 21-cm absorption surveys like the ASKAP First Large Absorption Survey in ${\\rm H\\, {\\small I}}$.
Publisher: Oxford University Press (OUP)
Date: 29-04-2015
DOI: 10.1093/MNRAS/STV677
Publisher: Oxford University Press (OUP)
Date: 13-05-2015
DOI: 10.1093/MNRAS/STV831
Publisher: Oxford University Press (OUP)
Date: 24-07-2015
Publisher: Oxford University Press (OUP)
Date: 17-02-2017
DOI: 10.1093/MNRAS/STX418
Publisher: Oxford University Press (OUP)
Date: 02-07-2014
Publisher: Cambridge University Press (CUP)
Date: 07-2015
DOI: 10.1017/S1743921314009570
Abstract: The SAGES Legacy Unifying Galaxies and GlobularS (SLUGGS) survey probes the outskirts of early-type galaxies (ETGs). SLUGGS uses the DEIMOS spectrograph on Keck to simultaneously obtain globular cluster and spatially resolved galaxy spectra. The galaxy spectra allow for the reconstruction of kinematic maps out to ∼3 effective radii ( R e ), while globular clusters (GCs) push the galactocentric limit out to ∼8–10 R e . Stellar population parameters (abundances) can also be recovered. This provides a unique dataset for exploring the outer gradients (abundance and/or kinematic transition). We briefly present recent and salient results of the SLUGGS survey so far.
Publisher: Oxford University Press (OUP)
Date: 08-09-2017
Publisher: American Astronomical Society
Date: 21-07-2017
Publisher: Oxford University Press (OUP)
Date: 02-07-2013
Publisher: American Astronomical Society
Date: 16-02-2017
Publisher: Oxford University Press (OUP)
Date: 04-09-2013
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.
Publisher: Oxford University Press (OUP)
Date: 17-02-2014
DOI: 10.1093/MNRAS/STU119
Publisher: Oxford University Press (OUP)
Date: 21-08-2023
Publisher: Elsevier BV
Date: 11-2015
Publisher: Oxford University Press (OUP)
Date: 14-12-2013
Publisher: Oxford University Press (OUP)
Date: 02-2021
Abstract: We have entered a new era where integral-field spectroscopic surveys of galaxies are sufficiently large to adequately s le large-scale structure over a cosmologically significant volume. This was the primary design goal of the SAMI Galaxy Survey. Here, in Data Release 3, we release data for the full s le of 3068 unique galaxies observed. This includes the SAMI cluster s le of 888 unique galaxies for the first time. For each galaxy, there are two primary spectral cubes covering the blue (370–570 nm) and red (630–740 nm) optical wavelength ranges at spectral resolving power of R = 1808 and 4304, respectively. For each primary cube, we also provide three spatially binned spectral cubes and a set of standardized aperture spectra. For each galaxy, we include complete 2D maps from parametrized fitting to the emission-line and absorption-line spectral data. These maps provide information on the gas ionization and kinematics, stellar kinematics and populations, and more. All data are available online through Australian Astronomical Optics Data Central.
Publisher: Oxford University Press (OUP)
Date: 24-09-2012
Publisher: American Astronomical Society
Date: 02-03-2012
Publisher: Oxford University Press (OUP)
Date: 31-08-2018
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.
Publisher: American Astronomical Society
Date: 29-04-2015
Publisher: American Astronomical Society
Date: 23-07-2015
Publisher: EDP Sciences
Date: 28-04-2016
Publisher: Oxford University Press (OUP)
Date: 12-10-2019
Abstract: We study the behaviour of the spin-ellipticity radial tracks for 507 galaxies from the Sydney AAO Multiobject Integral Field (SAMI) Galaxy Survey with stellar kinematics out to ≥1.5Re. We advocate for a morpho-dynamical classification of galaxies, relying on spatially resolved photometric and kinematic data. We find the use of spin-ellipticity radial tracks is valuable in identifying substructures within a galaxy, including embedded and counter-rotating discs, that are easily missed in unilateral studies of the photometry alone. Conversely, bars are rarely apparent in the stellar kinematics but are readily identified on images. Consequently, we distinguish the spin-ellipticity radial tracks of seven morpho-dynamical types: elliptical, lenticular, early spiral, late spiral, barred spiral, embedded disc, and 2σ galaxies. The importance of probing beyond the inner radii of galaxies is highlighted by the characteristics of galactic features in the spin-ellipticity radial tracks present at larger radii. The density of information presented through spin-ellipticity radial tracks emphasizes a clear advantage to representing galaxies as a track, rather than a single point, in spin-ellipticity parameter space.
Publisher: American Astronomical Society
Date: 26-03-2018
Publisher: Oxford University Press (OUP)
Date: 12-09-2017
Publisher: Cambridge University Press (CUP)
Date: 2016
DOI: 10.1017/PASA.2016.29
Abstract: Integral field unit spectrographs allow the 2D exploration of the kinematics and stellar populations of galaxies, although they are generally restricted to small fields-of-view. Using the large field-of-view of the DEIMOS multislit spectrograph on Keck and our Stellar Kinematics using Multiple Slits technique, we are able to extract sky-subtracted stellar light spectra to large galactocentric radii. Here, we present a new DEIMOS mask design named SuperSKiMS that explores large spatial scales without sacrificing high spatial s ling. We simulate a set of observations with such a mask design on the nearby galaxy NGC 1023, measuring stellar kinematics and metallicities out to where the galaxy surface brightness is orders of magnitude fainter than the sky. With this technique we also reproduce the results from literature integral field spectroscopy in the innermost galaxy regions. In particular, we use the simulated NGC 1023 kinematics to model its total mass distribution to large radii, obtaining comparable results with those from published integral field unit observation. Finally, from new spectra of NGC 1023, we obtain stellar 2D kinematics and metallicity distributions that show good agreement with integral field spectroscopy results in the overlapping regions. In particular, we do not find a significant offset between our Stellar Kinematics using Multiple Slits and the ATLAS 3D stellar velocity dispersion at the same spatial locations.
Publisher: Oxford University Press (OUP)
Date: 20-11-2015
Publisher: Oxford University Press (OUP)
Date: 07-02-2013
DOI: 10.1093/MNRAS/STT030
Publisher: American Astronomical Society
Date: 13-12-2011
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.
Publisher: Oxford University Press (OUP)
Date: 13-07-2017
Publisher: Oxford University Press (OUP)
Date: 11-12-2017
Publisher: Cambridge University Press (CUP)
Date: 06-2019
DOI: 10.1017/S1743921319007944
Abstract: Many recent integral field spectroscopy (IFS) survey teams have used stellar kinematic maps combined with imaging to statistically infer the underlying distributions of galaxy intrinsic shapes. With now several IFS s les at our disposal, the method, which was originally proposed by M. Franx and collaborators in 1991, is gaining in popularity, having been so far applied to ATLAS 3D , SAMI, MANGA and MASSIVE. We present results showing that a commonly assumed relationship between dynamical and intrinsic shape alignment does not hold in Illustris, affecting our ability to recover accurate intrinsic shape distributions. A further implication is that so-called “prolate rotation”, where the bulk of stars in prolate galaxies are thought to rotate around the projected major axis, is a misnomer.
Publisher: Oxford University Press (OUP)
Date: 21-08-2023
Publisher: American Astronomical Society
Date: 2021
Abstract: We investigate the stellar populations of passive spiral galaxies as a function of mass and environment, using integral field spectroscopy data from the Sydney-AAO Multi-object Integral field spectrograph Galaxy Survey. Our s le consists of 52 cluster passive spirals and 18 group/field passive spirals, as well as a set of S0s used as a control s le. The age and [Z/H] estimated by measuring Lick absorption line strength indices both at the center and within 1 R e do not show a significant difference between the cluster and the field/group passive spirals. However, the field/group passive spirals with log( M ⋆ / M ⊙ ) ≳ 10.5 show decreasing [ α /Fe] along with stellar mass, which is ∼0.1 dex smaller than that of the cluster passive spirals. We also compare the stellar populations of passive spirals with S0s. In the clusters, we find that passive spirals show slightly younger age and lower [ α /Fe] than the S0s over the whole mass range. In the field/group, stellar populations show a similar trend between passive spirals and S0s. In particular, [ α /Fe] of the field/group S0s tend to be flattening with increasing mass above log( M ⋆ / M ⊙ ) ≳ 10.5, similar to the field/group passive spirals. We relate the age and [ α /Fe] of passive spirals to their mean infall time in phase space we find a positive correlation, in agreement with the prediction of numerical simulations. We discuss the environmental processes that can explain the observed trends. The results lead us to conclude that the formation of the passive spirals and their transformation into S0s may significantly depend on their environments.
Publisher: Oxford University Press (OUP)
Date: 08-07-2015
Publisher: Oxford University Press (OUP)
Date: 11-05-2013
Publisher: Oxford University Press (OUP)
Date: 25-10-2013
DOI: 10.1093/MNRAS/STS029
Publisher: Oxford University Press (OUP)
Date: 15-09-2021
Abstract: The kinematic morphology–density relation of galaxies is normally attributed to a changing distribution of galaxy stellar masses with the local environment. However, earlier studies were largely focused on slow rotators the dynamical properties of the overall population in relation to environment have received less attention. We use the SAMI Galaxy Survey to investigate the dynamical properties of ∼1800 early and late-type galaxies with log (M⋆/M⊙) & 9.5 as a function of mean environmental overdensity (Σ5) and their rank within a group or cluster. By classifying galaxies into fast and slow rotators, at fixed stellar mass above log (M⋆/M⊙) & 10.5, we detect a higher fraction (∼3.4σ) of slow rotators for group and cluster centrals and satellites as compared to isolated-central galaxies. We find similar results when using Σ5 as a tracer for environment. Focusing on the fast-rotator population, we also detect a significant correlation between galaxy kinematics and their stellar mass as well as the environment they are in. Specifically, by using inclination-corrected or intrinsic $\\lambda _{R_{\\rm {e}}}$ values, we find that, at fixed mass, satellite galaxies on average have the lowest $\\lambda _{\\, R_{\\rm {e}},\\rm {intr}}$, isolated-central galaxies have the highest $\\lambda _{\\, R_{\\rm {e}},\\rm {intr}}$, and group and cluster centrals lie in between. Similarly, galaxies in high-density environments have lower mean $\\lambda _{\\, R_{\\rm {e}},\\rm {intr}}$ values as compared to galaxies at low environmental density. However, at fixed Σ5, the mean $\\lambda _{\\, R_{\\rm {e}},\\rm {intr}}$ differences for low and high-mass galaxies are of similar magnitude as when varying Σ5 ($\\Delta \\lambda _{\\, R_{\\rm {e}},\\rm {intr}} \\sim 0.05$, with σrandom = 0.025, and σsyst & 0.03). Our results demonstrate that after stellar mass, environment plays a significant role in the creation of slow rotators, while for fast rotators we also detect an independent, albeit smaller, impact of mass and environment on their kinematic properties.
Publisher: Oxford University Press (OUP)
Date: 23-03-2017
DOI: 10.1093/MNRAS/STX713
Publisher: Oxford University Press (OUP)
Date: 20-03-0031
DOI: 10.1093/MNRAS/STT310
Publisher: Oxford University Press (OUP)
Date: 14-06-2018
Publisher: Oxford University Press (OUP)
Date: 10-2012
Publisher: Oxford University Press (OUP)
Date: 16-01-2018
DOI: 10.1093/MNRAS/STY127
Start Date: 2019
End Date: 2021
Funder: Australian Research Council
View Funded ActivityStart Date: 2021
End Date: 2025
Funder: Australian Research Council
View Funded ActivityStart Date: 2021
End Date: 2023
Funder: Australian Research Council
View Funded ActivityStart Date: 2006
End Date: 2007
Funder: Natural Sciences and Engineering Research Council
View Funded ActivityStart Date: 10-2021
End Date: 09-2024
Amount: $645,000.00
Funder: Australian Research Council
View Funded ActivityStart Date: 02-2022
End Date: 05-2026
Amount: $727,138.00
Funder: Australian Research Council
View Funded Activity