ORCID Profile
0000-0002-1283-8420
Current Organisation
University of Oxford
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Publisher: American Astronomical Society
Date: 16-03-2022
Abstract: This paper documents the seventeenth data release (DR17) from the Sloan Digital Sky Surveys the fifth and final release from the fourth phase (SDSS-IV). DR17 contains the complete release of the Mapping Nearby Galaxies at Apache Point Observatory (MaNGA) survey, which reached its goal of surveying over 10,000 nearby galaxies. The complete release of the MaNGA Stellar Library accompanies this data, providing observations of almost 30,000 stars through the MaNGA instrument during bright time. DR17 also contains the complete release of the Apache Point Observatory Galactic Evolution Experiment 2 survey that publicly releases infrared spectra of over 650,000 stars. The main s le from the Extended Baryon Oscillation Spectroscopic Survey (eBOSS), as well as the subsurvey Time Domain Spectroscopic Survey data were fully released in DR16. New single-fiber optical spectroscopy released in DR17 is from the SPectroscipic IDentification of ERosita Survey subsurvey and the eBOSS-RM program. Along with the primary data sets, DR17 includes 25 new or updated value-added catalogs. This paper concludes the release of SDSS-IV survey data. SDSS continues into its fifth phase with observations already underway for the Milky Way Mapper, Local Volume Mapper, and Black Hole Mapper surveys.
Publisher: Oxford University Press (OUP)
Date: 22-03-2014
DOI: 10.1093/MNRAS/STU330
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.
Publisher: Elsevier BV
Date: 02-2007
Publisher: SPIE
Date: 30-09-2004
DOI: 10.1117/12.552912
Publisher: AIP
Date: 2008
DOI: 10.1063/1.2973563
Publisher: Cambridge University Press (CUP)
Date: 07-2014
DOI: 10.1017/S1743921314009922
Abstract: We present the KMOS ( K -band M ulti- O bject S pectrograph) Cluster and VIRIAL ( V LT IR I FU A bsorption L ine) Guaranteed Time Observation (GTO) programs. KMOS provides 24 arms each feeding an integral field unit (14×14 spaxels of 0.2″ pixels) for IZ, YJ, H and K band near infrared (NIR) medium resolution spectroscopy (R ∼ 3500). Targets are selected from a 7.2′ diameter patrol field. Ultra-deep spectroscopy of ∼ 80 early-type cluster galaxies (∼ 20hr on source) and ∼ 200 (∼ 10hr on source) early-type field galaxies at 1 z 2 will dramatically improve the situation at z 1 for which measurements of stellar velocity dispersions and absorption indices are limited to a few, often relatively young passively evolving galaxies (e.g. Bezanson 2013). In ESO Periods P92 and P93, 15 nights worth of data has been collected for KMOS-Clusters and 6 nights for VIRIAL: this will be supplemented with more data in upcoming semesters. All galaxies have multiband HST imaging including existing or upcoming WFC3 IR imaging, providing stellar mass maps and sizes. Combined with our dispersion measurements, this will allow us to examine the fundamental plane and the dynamical mass of a large s le of z 1 galaxies for the first time, for both cluster and field galaxies.
Publisher: American Astronomical Society
Date: 25-06-2020
Abstract: This paper documents the 16th data release (DR16) from the Sloan Digital Sky Surveys (SDSS), the fourth and penultimate from the fourth phase (SDSS-IV). This is the first release of data from the Southern Hemisphere survey of the Apache Point Observatory Galactic Evolution Experiment 2 (APOGEE-2) new data from APOGEE-2 North are also included. DR16 is also notable as the final data release for the main cosmological program of the Extended Baryon Oscillation Spectroscopic Survey (eBOSS), and all raw and reduced spectra from that project are released here. DR16 also includes all the data from the Time Domain Spectroscopic Survey and new data from the SPectroscopic IDentification of ERosita Survey programs, both of which were co-observed on eBOSS plates. DR16 has no new data from the Mapping Nearby Galaxies at Apache Point Observatory (MaNGA) survey (or the MaNGA Stellar Library “MaStar”). We also preview future SDSS-V operations (due to start in 2020), and summarize plans for the final SDSS-IV data release (DR17).
Publisher: American Astronomical Society
Date: 15-05-2018
Publisher: American Astronomical Society
Date: 29-06-2017
Publisher: SPIE
Date: 16-07-2010
DOI: 10.1117/12.856572
Publisher: Oxford University Press (OUP)
Date: 23-03-2018
DOI: 10.1093/MNRAS/STY778
Publisher: Oxford University Press (OUP)
Date: 23-10-2017
Publisher: Oxford University Press (OUP)
Date: 11-11-2009
Publisher: EDP Sciences
Date: 03-2022
DOI: 10.1051/0004-6361/202142614
Abstract: We present the blind Westerbork Coma Survey probing the H I content of the Coma galaxy cluster with the Westerbork Synthesis Radio Telescope. The survey covers the inner ∼1 Mpc around the cluster centre, extending out to 1.5 Mpc towards the south-western NGC 4839 group. The survey probes the atomic gas in the entire Coma volume down to a sensitivity of ∼10 19 cm −2 and 10 8 M ⊙ . Combining automated source finding with source extraction at optical redshifts and visual verification, we obtained 40 H I detections of which 24 are new. Over half of the s le displays perturbed H I morphologies indicative of an ongoing interaction with the cluster environment. With the use of ancillary UV and mid-IR, data we measured their stellar masses and star formation rates and compared the H I properties to a set of field galaxies spanning a similar stellar mass and star formation rate range. We find that ∼75% of H I -selected Coma galaxies have simultaneously enhanced star formation rates (by ∼0.2 dex) and are H I deficient (by ∼0.5 dex) compared to field galaxies of the same stellar mass. According to our toy model, the simultaneous H I deficiency and enhanced star formation activity can be attributed to either H I stripping of already highly star forming galaxies on a very short timescale, while their H 2 content remains largely unaffected, or to H I stripping coupled to a temporary boost of the H I -to-H 2 conversion, causing a brief starburst phase triggered by ram pressure before eventually quenching the galaxy.
Publisher: American Astronomical Society
Date: 30-07-2010
Publisher: American Astronomical Society
Date: 19-04-2018
Publisher: Cambridge University Press (CUP)
Date: 07-2014
DOI: 10.1017/S174392131500349X
Abstract: KMOS is a cryogenic infrared spectrograph fed by twentyfour deployable integral field units that patrol a 7.2 arcminute diameter field of view at the Nasmyth focus of the ESO VLT. It is well suited to the study of galaxy clusters at 1 z 2 where the well understood features in the restframe V-band are shifted into the KMOS spectral bands. Coupled with HST imagining, KMOS offers a window on the critical epoch for galaxy evolution, 7-10 Gyrs ago, when the key properties of cluster galaxies were established. We aim to investigate the size, mass, morphology and star formation history of galaxies in the clusters. Here we describe the instrument, discuss the status of the observations and report some preliminary results.
Publisher: EDP Sciences
Date: 07-2023
DOI: 10.1051/0004-6361/202346291
Abstract: According to the Λ cold dark matter (ΛCDM) cosmology, present-day galaxies with stellar masses M ⋆ 10 11 M ⊙ should contain a sizable fraction of dark matter within their stellar body. Models indicate that in massive early-type galaxies (ETGs) with M ⋆ ≈ 1.5 × 10 11 M ⊙ , dark matter should account for ∼15% of the dynamical mass within one effective radius (1 R e ) and for ∼60% within 5 R e . Most massive ETGs have been shaped through a two-phase process: the rapid growth of a compact core was followed by the accretion of an extended envelope through mergers. The exceedingly rare galaxies that have avoided the second phase, the so-called relic galaxies, are thought to be the frozen remains of the massive ETG population at z ≳ 2. The best relic galaxy candidate discovered to date is NGC 1277, in the Perseus cluster. We used deep integral field George and Cynthia Mitchel Spectrograph (GCMS) data to revisit NGC 1277 out to an unprecedented radius of 6 kpc (corresponding to 5 R e ). By using Jeans anisotropic modelling, we find a negligible dark matter fraction within 5 R e ( f DM (5 R e ) 0.05 two-sigma confidence level), which is in tension with the ΛCDM expectation. Since the lack of an extended envelope would reduce dynamical friction and prevent the accretion of an envelope, we propose that NGC 1277 lost its dark matter very early or that it was dark matter deficient ab initio. We discuss our discovery in the framework of recent proposals, suggesting that some relic galaxies may result from dark matter stripping as they fell in and interacted within galaxy clusters. Alternatively, NGC 1277 might have been born in a high-velocity collision of gas-rich proto-galactic fragments, where dark matter left behind a disc of dissipative baryons. We speculate that the relative velocities of ≈2000 km s −1 required for the latter process to happen were possible in the progenitors of the present-day rich galaxy clusters.
Publisher: American Astronomical Society
Date: 08-09-2017
Publisher: Oxford University Press (OUP)
Date: 11-03-2005
Publisher: American Astronomical Society
Date: 04-12-2017
Publisher: Oxford University Press (OUP)
Date: 13-08-2012
Publisher: American Astronomical Society
Date: 14-02-2019
Publisher: EDP Sciences
Date: 09-2015
Publisher: Oxford University Press (OUP)
Date: 05-08-2020
Abstract: The morphology of galaxies gives essential constraints on the models of galaxy evolution. The morphology of the features in the low-surface-brightness (LSB) regions of galaxies has not been fully explored yet because of observational difficulties. Here we present the results of our visual inspections of very deep images of a large volume-limited s le of 177 nearby massive early-type galaxies from the MATLAS survey. The images reach a surface-brightness limit of 28.5–29 mag arcsec−2 in the g′ band. Using a dedicated navigation tool and questionnaire, we looked for structures at the outskirts of the galaxies such as tidal shells, streams, tails, disturbed outer isophotes, or peripheral star-forming discs, and simultaneously noted the presence of contaminating sources, such as Galactic cirrus. We also inspected internal substructures such as bars and dust lanes. We discuss the reliability of this visual classification investigating the variety of answers made by the participants. We present the incidence of these structures and the trends of the incidence with the mass of the host galaxy and the density of its environment. We find an incidence of shells, stream, and tails of approximately 15 per cent, about the same for each category. For galaxies with masses over 1011 M⊙, the incidence of shells and streams increases about 1.7 times. We also note a strong unexpected anticorrelation of the incidence of Galactic cirrus with the environment density of the target galaxy. Correlations with other properties of the galaxies, and comparisons to model predictions, will be presented in future papers.
Publisher: Oxford University Press (OUP)
Date: 19-01-2017
DOI: 10.1093/MNRAS/STX101
Publisher: Oxford University Press (OUP)
Date: 24-04-2014
DOI: 10.1093/MNRAS/STU472
Publisher: American Astronomical Society
Date: 20-03-2018
Publisher: Oxford University Press (OUP)
Date: 26-06-2020
Abstract: Galaxy clusters have long been theorized to quench the star formation of their members. This study uses integral-field unit observations from the K-band MultiObject Spectrograph (KMOS) – Cluster Lensing And Supernova survey with Hubble (CLASH) survey (K-CLASH) to search for evidence of quenching in massive galaxy clusters at redshifts 0.3 & z & 0.6. We first construct mass-matched s les of exclusively star-forming cluster and field galaxies, then investigate the spatial extent of their H α emission and study their interstellar medium conditions using emission line ratios. The average ratio of H α half-light radius to optical half-light radius ($r_{\\mathrm{e}, {\\rm {H}\\,\\alpha }}/r_{\\mathrm{e}, R_{\\mathrm{c} } }$) for all galaxies is 1.14 ± 0.06, showing that star formation is taking place throughout stellar discs at these redshifts. However, on average, cluster galaxies have a smaller $r_{\\mathrm{e}, {\\rm {H}\\alpha }}/r_{\\mathrm{e}, R_{\\mathrm{c} } }$ ratio than field galaxies: 〈$r_{\\mathrm{e}, {\\rm {H}\\alpha }}/r_{\\mathrm{e}, R_{\\mathrm{c} } }$〉 = 0.96 ± 0.09 compared to 1.22 ± 0.08 (smaller at a 98 per cent credibility level). These values are uncorrected for the wavelength difference between H α emission and Rc-band stellar light but implementing such a correction only reinforces our results. We also show that whilst the cluster and field s les follow indistinguishable mass–metallicity (MZ) relations, the residuals around the MZ relation of cluster members correlate with cluster-centric distance galaxies residing closer to the cluster centre tend to have enhanced metallicities (significant at the 2.6σ level). Finally, in contrast to previous studies, we find no significant differences in electron number density between the cluster and field galaxies. We use simple chemical evolution models to conclude that the effects of disc strangulation and ram-pressure stripping can quantitatively explain our observations.
Publisher: AIP
Date: 2010
DOI: 10.1063/1.3458490
Publisher: American Astronomical Society
Date: 12-2021
Publisher: EDP Sciences
Date: 03-2020
DOI: 10.1051/0004-6361/201937040
Abstract: We study the evidence for a ersity of formation processes in early-type galaxies by presenting the first complete volume-limited s le of slow rotators with both integral-field kinematics from the ATLAS 3D Project and high spatial resolution photometry from the Hubble Space Telescope. Analysing the nuclear surface brightness profiles of 12 newly imaged slow rotators, we classify their light profiles as core-less, and place an upper limit to the core size of about 10 pc. Considering the full magnitude and volume-limited ATLAS 3D s le, we correlate the presence or lack of cores with stellar kinematics, including the proxy for the stellar angular momentum ( λ Re ) and the velocity dispersion within one half-light radius ( σ e ), stellar mass, stellar age, α -element abundance, and age and metallicity gradients. More than half of the slow rotators have core-less light profiles, and they are all less massive than 10 11 M ⊙ . Core-less slow rotators show evidence for counter-rotating flattened structures, have steeper metallicity gradients, and a larger dispersion of gradient values (Δ[Z/H]¯ = −0.42 ± 0.18) than core slow rotators (Δ[Z/H]¯ = −0.23 ± 0.07). Our results suggest that core and core-less slow rotators have different assembly processes, where the former, as previously discussed, are the relics of massive dissipation-less merging in the presence of central supermassive black holes. Formation processes of core-less slow rotators are consistent with accretion of counter-rotating gas or gas-rich mergers of special orbital configurations, which lower the final net angular momentum of stars, but support star formation. We also highlight core fast rotators as galaxies that share properties of core slow rotators (i.e. cores, ages, σ e , and population gradients) and core-less slow rotators (i.e. kinematics, λ Re , mass, and larger spread in population gradients). Formation processes similar to those for core-less slow rotators can be invoked to explain the assembly of core fast rotators, with the distinction that these processes form or preserve cores.
Publisher: American Astronomical Society
Date: 26-10-2021
Publisher: Springer Science and Business Media LLC
Date: 25-05-2016
DOI: 10.1038/NATURE18006
Abstract: Quiescent galaxies with little or no ongoing star formation dominate the population of galaxies with masses above 2 × 10(10) times that of the Sun the number of quiescent galaxies has increased by a factor of about 25 over the past ten billion years (refs 1-4). Once star formation has been shut down, perhaps during the quasar phase of rapid accretion onto a supermassive black hole, an unknown mechanism must remove or heat the gas that is subsequently accreted from either stellar mass loss or mergers and that would otherwise cool to form stars. Energy output from a black hole accreting at a low rate has been proposed, but observational evidence for this in the form of expanding hot gas shells is indirect and limited to radio galaxies at the centres of clusters, which are too rare to explain the vast majority of the quiescent population. Here we report bisymmetric emission features co-aligned with strong ionized-gas velocity gradients from which we infer the presence of centrally driven winds in typical quiescent galaxies that host low-luminosity active nuclei. These galaxies are surprisingly common, accounting for as much as ten per cent of the quiescent population with masses around 2 × 10(10) times that of the Sun. In a prototypical ex le, we calculate that the energy input from the galaxy's low-level active supermassive black hole is capable of driving the observed wind, which contains sufficient mechanical energy to heat ambient, cooler gas (also detected) and thereby suppress star formation.
Publisher: Oxford University Press (OUP)
Date: 08-2006
Publisher: Oxford University Press (OUP)
Date: 24-07-2018
Publisher: Oxford University Press (OUP)
Date: 21-03-2006
Publisher: American Astronomical Society
Date: 13-11-2017
Publisher: American Astronomical Society
Date: 14-04-2010
Publisher: American Astronomical Society
Date: 10-12-2014
Publisher: IOP Publishing
Date: 26-04-2005
Publisher: American Astronomical Society
Date: 29-04-2015
Publisher: Oxford University Press (OUP)
Date: 20-06-2016
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: 26-04-2020
Abstract: We study a s le of 148 early-type galaxies in the Coma cluster using SDSS photometry and spectra, and calibrate our results using detailed dynamical models for a subset of these galaxies, to create a precise benchmark for dynamical scaling relations in high-density environments. For these galaxies, we successfully measured global galaxy properties, modelled stellar populations, and created dynamical models, and support the results using detailed dynamical models of 16 galaxies, including the two most massive cluster galaxies, using data taken with the SAURON IFU. By design, the study provides minimal scatter in derived scaling relations due to the small uncertainty in the relative distances of galaxies compared to the cluster distance. Our results demonstrate low (≤55 per cent for 90th percentile) dark matter fractions in the inner 1Re of galaxies. Owing to the study design, we produce the tightest, to our knowledge, IMF–σe relation of galaxies, with a slope consistent with that seen in local galaxies. Leveraging our dynamical models, we transform the classical Fundamental Plane of the galaxies to the Mass Plane. We find that the coefficients of the Mass Plane are close to predictions from the virial theorem, and have significantly lower scatter compared to the Fundamental Plane. We show that Coma galaxies occupy similar locations in the (M*–Re) and (M*−σe) relations as local field galaxies but are older. This, and the fact we find only three slow rotators in the cluster, is consistent with the scenario of hierarchical galaxy formation and expectations of the kinematic morphology–density relation.
Publisher: EDP Sciences
Date: 05-2019
DOI: 10.1051/0004-6361/201834808
Abstract: Different massive black hole mass – host galaxy scaling relations suggest that the growth of massive black holes is entangled with the evolution of their host galaxies. The number of measured black hole masses is still limited and additional measurements are necessary to understand the underlying physics of this apparent coevolution. We add six new black hole mass ( M BH ) measurements of nearby fast rotating early-type galaxies to the known black hole mass s le, namely NGC 584, NGC 2784, NGC 3640, NGC 4570, NGC 4281, and NGC 7049. Our target galaxies have effective velocity dispersions ( σ e ) between 170 and 245 km s −1 , and thus this work provides additional insight into the black hole properties of intermediate-mass early-type galaxies. We combined high-resolution adaptive-optics SINFONI data with large-scale MUSE, VIMOS and SAURON data from ATLAS 3D to derive two-dimensional stellar kinematics maps. We then built both Jeans Anisotropic Models and axisymmetric Schwarzschild models to measure the central black hole masses. Our Schwarzschild models provide black hole masses of (1.3 ± 0.5) × 10 8 M ⊙ for NGC 584, (1.0 ± 0.6) × 10 8 M ⊙ for NGC 2784, (7.7 ± 5) × 10 7 M ⊙ for NGC 3640, (5.4 ± 0.8) × 10 8 M ⊙ for NGC 4281, (6.8 ± 2.0) × 10 7 M ⊙ for NGC 4570, and (3.2 ± 0.8) × 10 8 M ⊙ for NGC 7049 at 3 σ confidence level, which are consistent with recent M BH − σ e scaling relations. NGC 3640 has a velocity dispersion dip and NGC 7049 a constant velocity dispersion in the center, but we can clearly constrain their lower black hole mass limit. We conclude our analysis with a test on NGC 4570 taking into account a variable mass-to-light ratio ( M / L ) when constructing dynamical models. When considering M / L variations linked mostly to radial changes in the stellar metallicity, we find that the dynamically determined black hole mass from NGC 4570 decreases by 30%. Further investigations are needed in the future to account for the impact of radial M / L gradients on dynamical modeling.
Publisher: Oxford University Press (OUP)
Date: 08-2006
Publisher: American Astronomical Society
Date: 11-05-2018
Publisher: Oxford University Press (OUP)
Date: 07-03-2016
DOI: 10.1093/MNRAS/STW502
Publisher: EDP Sciences
Date: 19-12-2016
Publisher: American Astronomical Society
Date: 13-08-2015
Location: United Kingdom of Great Britain and Northern Ireland
No related grants have been discovered for Michele Cappellari.