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Full-Text Articles in Physical Sciences and Mathematics

The Causes Of The Red Sequence, The Blue Cloud, The Green Valley, And The Green Mountain, Stephen A. Eales, Maarten Baes, Nathan Bourne, Malcolm Bremer, Michael J.I. Brown, Christopher Clark, David Clements, Pieter De Vis, Simon Driver, Loretta Dunne, Simon Dye, Cristina Furlanetto, Benne W. Holwerda, R. J. Ivison, L. S. Kelvin, Maritza Lara-Lopez, Lerothodi Leeuw, Jon Loveday, Steve Maddox, Michal J. Michalowski, Steven Phillipps, Aaron Robotham, Dan Smith, Matthew Smith, Elisabetta Valiante, Paul Van Der Werf, Angus Wright Nov 2018

The Causes Of The Red Sequence, The Blue Cloud, The Green Valley, And The Green Mountain, Stephen A. Eales, Maarten Baes, Nathan Bourne, Malcolm Bremer, Michael J.I. Brown, Christopher Clark, David Clements, Pieter De Vis, Simon Driver, Loretta Dunne, Simon Dye, Cristina Furlanetto, Benne W. Holwerda, R. J. Ivison, L. S. Kelvin, Maritza Lara-Lopez, Lerothodi Leeuw, Jon Loveday, Steve Maddox, Michal J. Michalowski, Steven Phillipps, Aaron Robotham, Dan Smith, Matthew Smith, Elisabetta Valiante, Paul Van Der Werf, Angus Wright

Faculty Scholarship

The galaxies found in optical surveys fall in two distinct regions of a diagram of optical colour versus absolute magnitude: the red sequence and the blue cloud, with the green valley in between. We show that the galaxies found in a submillimetre survey have almost the opposite distribution in this diagram, forming a 'green mountain'. We show that these distinctive distributions follow naturally from a single, continuous, curved Galaxy Sequence in a diagram of specific star formation rate versus stellar mass, without there being the need for a separate star-forming galaxy main sequence and region of passive galaxies. The cause …


Studying The [O Iii]Λ5007 Å Emission-Line Width In A Sample Of ∼ 80 Local Active Galaxies: A Surrogate For Σ⋆?, Vardha Nicola Bennert, Donald Loveland, Edward Donohue, Maren Cosens, Sean Lewis, S. Komossa, Tommaso Treu, Matthew A. Malkan, Nathan Milgram, Kelsi Flatland, Matthew W. Auger, Daesong Park, Mariana S. Lazarova Nov 2018

Studying The [O Iii]Λ5007 Å Emission-Line Width In A Sample Of ∼ 80 Local Active Galaxies: A Surrogate For Σ⋆?, Vardha Nicola Bennert, Donald Loveland, Edward Donohue, Maren Cosens, Sean Lewis, S. Komossa, Tommaso Treu, Matthew A. Malkan, Nathan Milgram, Kelsi Flatland, Matthew W. Auger, Daesong Park, Mariana S. Lazarova

Physics

For a sample of ∼ 80 local (0.02 ≤ z" role="presentation">z ≤ 0.1) Seyfert-1 galaxies with high-quality long-slit Keck spectra and spatially resolved stellar-velocity dispersion (σ) measurements, we study the profile of the [O iii]λ5007 Å emission line to test the validity of using its width as a surrogate for σ. Such an approach has often been used in the literature, since it is difficult to measure σ for type-1 active galactic nuclei (AGNs) due to the AGN continuum outshining the stellar-absorption lines. Fitting the [O iii] line with a single Gaussian or Gauss–Hermite …


Deep Extragalactic Visible Legacy Survey (Devils): Motivation, Design, And Target Catalogue, L. J.M. Davies, A. S.G. Robotham, S. P. Driver, C. P. Lagos, L. Cortese, E. Mannering, C. Foster, C. Lidman, A. Hashemizadeh, S. Koushan, S. O'Toole, I. K. Baldry, M. Bilicki, J. Bland-Hawthorn, M. N. Bremer, M. J.I. Brown, J. J. Bryant, B. Catinella, S. M. Croom, M. W. Grootes, Benne W. Holwerda, M. J. Jarvis, N. Maddox, M. Meyer, A. J. Moffett, S. Phillipps, E. N. Taylor, R. A. Windhorst, C. Wolf Oct 2018

Deep Extragalactic Visible Legacy Survey (Devils): Motivation, Design, And Target Catalogue, L. J.M. Davies, A. S.G. Robotham, S. P. Driver, C. P. Lagos, L. Cortese, E. Mannering, C. Foster, C. Lidman, A. Hashemizadeh, S. Koushan, S. O'Toole, I. K. Baldry, M. Bilicki, J. Bland-Hawthorn, M. N. Bremer, M. J.I. Brown, J. J. Bryant, B. Catinella, S. M. Croom, M. W. Grootes, Benne W. Holwerda, M. J. Jarvis, N. Maddox, M. Meyer, A. J. Moffett, S. Phillipps, E. N. Taylor, R. A. Windhorst, C. Wolf

Faculty Scholarship

The Deep Extragalactic VIsible Legacy Survey (DEVILS) is a large spectroscopic campaign at the Anglo-Australian Telescope (AAT) aimed at bridging the near and distant Universe by producing the highest completeness survey of galaxies and groups at intermediate redshifts (0.3 < z < 1.0). Our sample consists of ~60 000 galaxies to Y < 21.2mag, over ~6 deg2 in threewell-studied deep extragalactic fields (Cosmic Origins Survey field, COSMOS; Extended Chandra Deep Field South, ECDFS; and the X-ray Multi-Mirror Mission Large-Scale Structure region, XMM-LSS - all Large Synoptic Survey Telescope deep-drill fields). This paper presents the broad experimental design of DEVILS. Our target sample has been selected from deep Visible and Infrared Survey Telescope for Astronomy (VISTA) Y-band imaging (VISTA Deep Extragalactic Observations, VIDEO and UltraVISTA), with photometry measured by PROFOUND. Photometric star/galaxy separation is done on the basis of near-infrared colours and has been validated by visual inspection. To maximize our observing efficiency for faint targets, we employ a redshift feedback strategy, which continually updates our target lists, feeding back the results from the previous night's observations. We also present an overview of the initial spectroscopic observations undertaken in late 2017 and early 2018.


Origins Of Ultradiffuse Galaxies In The Coma Cluster – Ii. Constraints From Their Stellar Populations, Anna Ferre-Mateu, Adebusola Alabi, Duncan Forbes, Aaron Romanowsky, Jean Brodie, Viraj Pandya, Ignacio Mart´In-Navarro, Sabine Bellstedt, Asher Wasserman, Maria Stone, Nobuhiro Okabe Oct 2018

Origins Of Ultradiffuse Galaxies In The Coma Cluster – Ii. Constraints From Their Stellar Populations, Anna Ferre-Mateu, Adebusola Alabi, Duncan Forbes, Aaron Romanowsky, Jean Brodie, Viraj Pandya, Ignacio Mart´In-Navarro, Sabine Bellstedt, Asher Wasserman, Maria Stone, Nobuhiro Okabe

Faculty Publications

In this second paper of the series we study, with new Keck/DEIMOS spectra, the stellar populations of seven spectroscopically confirmed ultradiffuse galaxies (UDGs) in the Coma cluster. We find intermediate to old ages (∼7 Gyr), low metallicities ([Z/H] ∼ −0.7 dex) and mostly supersolar abundance patterns ([Mg/Fe] ∼ 0.13 dex). These properties are similar to those of low-luminosity (dwarf) galaxies inhabiting the same area in the cluster and are mostly consistent with being the continuity of the stellar mass scaling relations of more massive galaxies. These UDGs’ star formation histories imply a relatively recent infall into the Coma cluster, consistent …


Galaxy And Mass Assembly (Gama): The Environmental Dependence Of The Galaxy Main Sequence, L. Wang, P. Norberg, S. Brough, M. J.I. Brown, E. Da Cunha, L. J. Davies, S. P. Driver, Benne W. Holwerda, A. M. Hopkins, M. A. Lara-Lopez, J. Liske, J. Loveday, M. W. Grootes, C. C. Popescu, A. H. Wright Oct 2018

Galaxy And Mass Assembly (Gama): The Environmental Dependence Of The Galaxy Main Sequence, L. Wang, P. Norberg, S. Brough, M. J.I. Brown, E. Da Cunha, L. J. Davies, S. P. Driver, Benne W. Holwerda, A. M. Hopkins, M. A. Lara-Lopez, J. Liske, J. Loveday, M. W. Grootes, C. C. Popescu, A. H. Wright

Faculty Scholarship

Aims: We aim to investigate if the environment (characterised by the host dark matter halo mass) plays any role in shaping the galaxy star formation main sequence (MS). Methods: The Galaxy and Mass Assembly project (GAMA) combines a spectroscopic survey with photometric information in 21 bands from the far-ultraviolet (FUV) to the far-infrared (FIR). Stellar masses and dust-corrected star-formation rates (SFR) are derived from spectral energy distribution (SED) modelling using MAGPHYS. We use the GAMA galaxy group catalogue to examine the variation of the fraction of star-forming galaxies (SFG) and properties of the MS with respect to the environment. Results: …


Origins Of Ultradiffuse Galaxies In The Coma Cluster – I. Constraints From Velocity Phase Space, Adebusola Alabi, Anna Ferré-Mateu, Aaron Romanowsky, Jean Brodie, Duncan Forbes, Asher Wasserman, Sabine Bellstedt, Ignacio Martín-Navarro, Viraj Pandya, Maria Stone, Nobuhiro Okabe Sep 2018

Origins Of Ultradiffuse Galaxies In The Coma Cluster – I. Constraints From Velocity Phase Space, Adebusola Alabi, Anna Ferré-Mateu, Aaron Romanowsky, Jean Brodie, Duncan Forbes, Asher Wasserman, Sabine Bellstedt, Ignacio Martín-Navarro, Viraj Pandya, Maria Stone, Nobuhiro Okabe

Faculty Publications

We use Keck/DEIMOS spectroscopy to confirm the cluster membership of 16 ultradiffuse galaxies (UDGs) in the Coma cluster, bringing the total number of spectroscopically confirmed UDGs from the Yagi et al. (Y16) catalogue to 25. We also identify a new cluster background UDG, confirming that most (∼95 per cent) of the UDGs in the Y16 catalogue belong to the Coma cluster. In this pilot study of Coma UDGs in velocity phase space, we find evidence of a diverse origin for Coma cluster UDGs, similar to normal dwarf galaxies. Some UDGs in our sample are consistent with being late infalls into …


The Distance Of The Dark Matter Deficient Galaxy Ngc 1052–Df2, Pieter Van Dokkum, Shany Danieli, Yotam Cohen, Aaron Romanowsky, Charlie Conroy Aug 2018

The Distance Of The Dark Matter Deficient Galaxy Ngc 1052–Df2, Pieter Van Dokkum, Shany Danieli, Yotam Cohen, Aaron Romanowsky, Charlie Conroy

Faculty Publications

We recently inferred that the galaxy NGC 1052–DF2 has little or no dark matter and a rich system of unusual globular clusters. We assumed that the galaxy is a satellite of the luminous elliptical galaxy NGC 1052 at ≈20 Mpc, on the basis of its surface brightness fluctuations (SBFs) distance of 19.0 ± 1.7 Mpc, its radial velocity of ≈1800 km s−1, and its projected position. Here we analyze the color–magnitude diagram (CMD) of NGC 1052–DF2, following the suggestion by Trujillo et al. that the tip of the red giant branch (TRGB) can be detected in currently available Hubble Space …


A 3.5 Million Solar Masses Black Hole In The Centre Of The Ultracompact Dwarf Galaxy Fornax Ucd3, Anton Afanasiev, Igor Chilingarian, Steffen Mieske, Karina Voggel, Arianna Picotti, Michael Hilker, Anil Seth, Nadine Neumayer, Matthias Frank, Aaron Romanowsky, George Hau, Holger Baumgardt, Christopher Ahn, Jay Strader, Mark Den Brok, Richard Mcdermid, Lee Spitler, Jean Brodie, Jonelle Walsh Jul 2018

A 3.5 Million Solar Masses Black Hole In The Centre Of The Ultracompact Dwarf Galaxy Fornax Ucd3, Anton Afanasiev, Igor Chilingarian, Steffen Mieske, Karina Voggel, Arianna Picotti, Michael Hilker, Anil Seth, Nadine Neumayer, Matthias Frank, Aaron Romanowsky, George Hau, Holger Baumgardt, Christopher Ahn, Jay Strader, Mark Den Brok, Richard Mcdermid, Lee Spitler, Jean Brodie, Jonelle Walsh

Faculty Publications

The origin of ultracompact dwarfs (UCDs), a class of compact stellar systems discovered two decades ago, still remains a matter of debate. Recent discoveries of central supermassive black holes in UCDs likely inherited from their massive progenitor galaxies provide support for the tidal stripping hypothesis. At the same time, on statistical grounds, some massive UCDs might be representatives of the high luminosity tail of the globular cluster luminosity function. Here we present a detection of a 3.3+1.4−1.2×106M⊙ black hole (1σ uncertainty) in the centre of the UCD3 galaxy in the Fornax cluster, which corresponds to 4 per cent of its …


The Sluggs Survey: A Comparison Of Total-Mass Profiles Of Early-Type Galaxies From Observations And Cosmological Simulations, To ∼4 Effective Radii, Sabine Bellstedt, Duncan Forbes, Aaron Romanowsky, Rhea-Silvia Remus, Adam Stevens, Jean Brodie, Adriano Poci, Richard Mcdermid, Adebusola Alabi, Leonie Chevalier, Caitlin Adams, Anna Ferré-Mateu, Asher Wasserman, Viraj Pandya Jun 2018

The Sluggs Survey: A Comparison Of Total-Mass Profiles Of Early-Type Galaxies From Observations And Cosmological Simulations, To ∼4 Effective Radii, Sabine Bellstedt, Duncan Forbes, Aaron Romanowsky, Rhea-Silvia Remus, Adam Stevens, Jean Brodie, Adriano Poci, Richard Mcdermid, Adebusola Alabi, Leonie Chevalier, Caitlin Adams, Anna Ferré-Mateu, Asher Wasserman, Viraj Pandya

Faculty Publications

We apply the Jeans Anisotropic Multi-Gaussian Expansion dynamical modelling method to SAGES Legacy Unifying Globulars and GalaxieS (SLUGGS) survey data of early-type galaxies in the stellar mass range 1010 < M*/M⊙ < 1011.6 that cover a large radial range of 0.1–4.0 effective radii. We combine SLUGGS and ATLAS3D data sets to model the total-mass profiles of a sample of 21 fast-rotator galaxies, utilizing a hyperparameter method to combine the two independent data sets. The total-mass density profile slope values derived for these galaxies are consistent with those measured in the inner regions of galaxies by other studies. Furthermore, the total-mass density slopes (γtot) appear to be universal over this broad stellar mass range, with an average value of γtot =  −2.24 ±  0.05 , i.e. slightly steeper than isothermal. We compare our results to model galaxies from the Magneticum and EAGLE cosmological hydrodynamic simulations, in order to probe the mechanisms that are responsible for varying total-mass density profile slopes. The simulated-galaxy slopes are shallower than the observed values by ∼0.3–0.5, indicating that the physical processes shaping the mass distributions of galaxies in cosmological simulations are still incomplete. For galaxies with M* > 1010.7 M⊙ in the Magneticum simulations, we identify a significant anticorrelation between total-mass density profile slopes and the fraction of stellar mass formed ex situ (i.e. accreted), whereas this anticorrelation is weaker for lower stellar masses, implying that the measured total-mass density slopes for low-mass galaxies are less likely to be determined by merger activity.


Galaxy And Mass Assembly (Gama): Morphological Transformation Of Galaxies Across The Green Valley, M. N. Bremer, S. Phillipps, S. Kelvin, R. De Propris, Rebecca Kennedy, Amanda J. Moffett, S. Bamford, L. J.M. Davies, S. P. Driver, B. Häußler, Benne W. Holwerda, A. Hopkins, P. A. James, J. Liske, S. Percival, N. Taylor May 2018

Galaxy And Mass Assembly (Gama): Morphological Transformation Of Galaxies Across The Green Valley, M. N. Bremer, S. Phillipps, S. Kelvin, R. De Propris, Rebecca Kennedy, Amanda J. Moffett, S. Bamford, L. J.M. Davies, S. P. Driver, B. Häußler, Benne W. Holwerda, A. Hopkins, P. A. James, J. Liske, S. Percival, N. Taylor

Faculty Scholarship

We explore constraints on the joint photometric and morphological evolution of typical low redshift galaxies as they move from the blue cloud through the green valley and on to the red sequence. We select Galaxy And Mass Assembly (GAMA) survey galaxies with 10.25 < log(M*/Mo˙) < 10.75 and z < 0.2 classified according to their intrinsic u* - r* colour. From single component Śersic fits, we find that the stellar mass-sensitive K-band profiles of red and green galaxy populations are very similar while g-band profiles indicate more disc-like morphologies for the green galaxies: apparent (optical) morphological differences arise primarily from radial mass-to-light ratio variations. Two-component fits show that most green galaxies have significant bulge and disc components and that the blue to red evolution is driven by colour change in the disc. Together, these strongly suggest that galaxies evolve from blue to red through secular disc fading and that a strong bulge is present prior to any decline in star formation. The relative abundance of the green population implies a typical time-scale for traversing the green valley ~1-2 Gyr and is independent of environment, unlike that of the red and blue populations. While environment likely plays a role in triggering the passage across the green valley, it appears to have little effect on time taken. These results are consistent with a green valley population dominated by (early type) disc galaxies that are insufficiently supplied with gas to maintain previous levels of disc star formation, eventually attaining passive colours. No single event is needed to quench their star formation.


The Stellar Populations Of Two Ultra-Diffuse Galaxies From Optical And Near-Infrared Photometry, Viraj Pandya, Aaron J. Romanowsky, Seppo Laine, Jean Brodie, Benjamin Johnson, William Glaccum, Alexa Villaume, Jean-Charles Cuillandre, Stephen Gwyn, Jessica Krick, Ronald Lasker, Ignacio Martín-Navarro, David Martinez-Delgado, Pieter Van Dokkum Apr 2018

The Stellar Populations Of Two Ultra-Diffuse Galaxies From Optical And Near-Infrared Photometry, Viraj Pandya, Aaron J. Romanowsky, Seppo Laine, Jean Brodie, Benjamin Johnson, William Glaccum, Alexa Villaume, Jean-Charles Cuillandre, Stephen Gwyn, Jessica Krick, Ronald Lasker, Ignacio Martín-Navarro, David Martinez-Delgado, Pieter Van Dokkum

Faculty Publications

We present observational constraints on the stellar populations of two ultra-diffuse galaxies (UDGs) using optical through near-infrared (NIR) spectral energy distribution (SED) fitting. Our analysis is enabled by new Spitzer-IRAC 3.6 and 4.5 μm imaging, archival optical imaging, and the prospectorfully Bayesian SED fitting framework. Our sample contains one field UDG (DGSAT I), one Virgo cluster UDG (VCC 1287), and one Virgo cluster dwarf elliptical for comparison (VCC 1122). We find that the optical–NIR colors of the three galaxies are significantly different from each other. We infer that VCC 1287 has an old (7.7 Gyr) and surprisingly metal-poor …


Galaxy And Mass Assembly (Gama): Blue Spheroids Within 87 Mpc, Smriti Mahajan, Michael J. Drinkwater, S. Driver, A. M. Hopkins, Alister W. Graham, S. Brough, Michael J.I. Brown, Benne W. Holwerda, Matt S. Owers, Kevin A. Pimbblet Mar 2018

Galaxy And Mass Assembly (Gama): Blue Spheroids Within 87 Mpc, Smriti Mahajan, Michael J. Drinkwater, S. Driver, A. M. Hopkins, Alister W. Graham, S. Brough, Michael J.I. Brown, Benne W. Holwerda, Matt S. Owers, Kevin A. Pimbblet

Faculty Scholarship

In this paper, we test if nearby blue spheroid (BSph) galaxies may become the progenitors of star-forming spiral galaxies or passively evolving elliptical galaxies. Our sample comprises 428 galaxies of various morphologies in the redshift range 0.002 < Ζ < 0.02 (8-87 Mpc) with panchromatic data from the Galaxy and Mass Assembly survey. We find that BSph galaxies are structurally (mean effective surface brightness, effective radius) very similar to their passively evolving red counterparts. However, their star formation and other properties such as colour, age, and metallicity are more like star-forming spirals than spheroids (ellipticals and lenticulars). We show that BSph galaxies are statistically distinguishable from other spheroids as well as spirals in the multidimensional space mapped by luminosity-weighted age, metallicity, dust mass, and specific star formation rate. We use HI data to reveal that some of the BSphs are (further) developing their discs, hence their blue colours. They may eventually become spiral galaxies - if sufficient gas accretion occurs - or more likely fade into low-mass red galaxies.


On The Formation Mechanisms Of Compact Elliptical Galaxies, Anna Ferré-Mateu, Duncan Forbes, Aaron Romanowsky, Joachim Janz, Christopher Dixon Jan 2018

On The Formation Mechanisms Of Compact Elliptical Galaxies, Anna Ferré-Mateu, Duncan Forbes, Aaron Romanowsky, Joachim Janz, Christopher Dixon

Faculty Publications

In order to investigate the formation mechanisms of the rare compact elliptical (cE) galaxies, we have compiled a sample of 25 cEs with good SDSS spectra, covering a range of stellar masses, sizes and environments. They have been visually classified according to the interaction with their host, representing different evolutionary stages. We have included clearly disrupted galaxies, galaxies that despite not showing signs of interaction are located close to a massive neighbour (thus are good candidates for a stripping process), and cEs with no host nearby. For the latter, tidal stripping is less likely to have happened and instead they …


Constraints On Radial Migration In Spiral Galaxies - Ii. Angular Momentum Distribution And Preferential Migration, Kathryne J. Daniel, Rosemary F. G. Wyse Jan 2018

Constraints On Radial Migration In Spiral Galaxies - Ii. Angular Momentum Distribution And Preferential Migration, Kathryne J. Daniel, Rosemary F. G. Wyse

Physics Faculty Research and Scholarship

The orbital angular momentum of individual stars in galactic discs can be permanently changed through torques from transient spiral patterns. Interactions at the corotation resonance dominate these changes and have the further property of conserving orbital circularity. We derived in an earlier paper an analytic criterion that an unperturbed stellar orbit must satisfy in order for such an interaction to occur i.e. for it to be in a trapped orbit around corotation. We here use this criterion in an investigation of how the efficiency of induced radial migration for a population of disc stars varies with the angular momentum distribution …


Constraints On Radial Migration In Spiral Galaxies – Ii. Angular Momentum Distribution And Preferential Migration, Kathryne J. Daniel, Rosemary F. G. Wyse Jan 2018

Constraints On Radial Migration In Spiral Galaxies – Ii. Angular Momentum Distribution And Preferential Migration, Kathryne J. Daniel, Rosemary F. G. Wyse

Physics Faculty Research and Scholarship

The orbital angular momentum of individual stars in galactic discs can be permanently changed through torques from transient spiral patterns. Interactions at the corotation resonance dominate these changes and have the further property of conserving orbital circularity. We derived in an earlier paper an analytic criterion that an unperturbed stellar orbit must satisfy in order for such an interaction to occur, i.e. for it to be in a trapped orbit around corotation. We here use this criterion in an investigation of how the efficiency of induced radial migration for a population of disc stars varies with the angular momentum distribution …


Galaxy And Mass Assembly (Gama): The Consistency Of Gama And Wise Derived Mass-To-Light Ratios, T. Kettlety, J. Hesling, S. Phillipps, M. N. Bremer, M. E. Cluver, E. N. Taylor, J. Bland-Hawthorn, S. Brough, R. De Propris, S. P. Driver, Benne W. Holwerda, L. S. Kelvin, W. Sutherland, A. H. Wright Jan 2018

Galaxy And Mass Assembly (Gama): The Consistency Of Gama And Wise Derived Mass-To-Light Ratios, T. Kettlety, J. Hesling, S. Phillipps, M. N. Bremer, M. E. Cluver, E. N. Taylor, J. Bland-Hawthorn, S. Brough, R. De Propris, S. P. Driver, Benne W. Holwerda, L. S. Kelvin, W. Sutherland, A. H. Wright

Faculty Scholarship

Recent work has suggested that mid-IR wavelengths are optimal for estimating the mass-to-light ratios of stellar populations and hence the stellar masses of galaxies. We compare stellar masses deduced from spectral energy distribution (SED) models, fitted to multiwavelength optical-NIR photometry, to luminosities derived from WISE photometry in the W1 and W2 bands at 3.6 and 4.5 μmfor non-star forming galaxies. The SED-derived masses for a carefully selected sample of low-redshift (z≤0.15) passive galaxies agree with the prediction from stellar population synthesis models such that M*/LW1 ≃0.6 for all such galaxies, independent of other stellar population parameters. The small scatter between …


Galaxy And Mass Assembly (Gama): The Mechanisms For Quiescent Galaxy Formation At Z < 1, K. Rowlands, V. Wild, N. Bourne, M. Bremer, S. Brough, S. P. Driver, A. M. Hopkins, M. S. Owers, S. Phillipps, K. Pimbblet, A. E. Sansom, L. Wang, M. Alpaslan, J. Bland-Hawthorn, M. Colless, Benne W. Holwerda, E. N. Taylor Jan 2018

Galaxy And Mass Assembly (Gama): The Mechanisms For Quiescent Galaxy Formation At Z < 1, K. Rowlands, V. Wild, N. Bourne, M. Bremer, S. Brough, S. P. Driver, A. M. Hopkins, M. S. Owers, S. Phillipps, K. Pimbblet, A. E. Sansom, L. Wang, M. Alpaslan, J. Bland-Hawthorn, M. Colless, Benne W. Holwerda, E. N. Taylor

Faculty Scholarship

One key problem in astrophysics is understanding how and why galaxies switch off their star formation, building the quiescent population that we observe in the local Universe. From the Galaxy And Mass Assembly and VIsible MultiObject Spectrograph Public Extragalactic Redshift surveys, we use spectroscopic indices to select quiescent and candidate transition galaxies. We identify potentially rapidly transitioning post-starburst (PSB) galaxies and slower transitioning green-valley galaxies. Over the last 8Gyr, the quiescent population has grown more slowly in number density at high masses (M* > 1011M⊙) than at intermediate masses (M* > 1010.6M⊙). There is evolution in both the PSB and green-valley stellar …