TY - JOUR

T1 - The LEGA-C and SAMI Galaxy Surveys

T2 - Quiescent Stellar Populations and the Mass-Size Plane across 6 Gyr

AU - Barone, Tania M.

AU - D'Eugenio, Francesco

AU - Scott, Nicholas

AU - Colless, Matthew

AU - Vaughan, Sam P.

AU - Wel, Arjen van der

AU - Fraser-McKelvie, Amelia

AU - Graaff, Anna de

AU - Sande, Jesse van de

AU - Wu, Po-Feng

AU - Bezanson, Rachel

AU - Brough, Sarah

AU - Bell, Eric

AU - Croom, Scott M.

AU - Cortese, Luca

AU - Driver, Simon

AU - Gallazzi, Anna R.

AU - Muzzin, Adam

AU - Sobral, David

AU - Bland-Hawthorn, Joss

AU - Bryant, Julia J.

AU - Goodwin, Michael

AU - Lawrence, Jon S.

AU - Lorente, Nuria P. F.

AU - Owers, Matt S.

N1 - This is a pre-copy-editing, author-produced PDF of an article accepted for publication in Monthly Notices of the Royal Astronomical Society following peer review. The definitive publisher-authenticated version Tania M Barone, Francesco D’Eugenio, Nicholas Scott, Matthew Colless, Sam P Vaughan, Arjen van der Wel, Amelia Fraser-McKelvie, Anna de Graaff, Jesse van de Sande, Po-Feng Wu(吳柏鋒), Rachel Bezanson, Sarah Brough, Eric Bell, Scott M Croom, Luca Cortese, Simon Driver, Anna R Gallazzi, Adam Muzzin, David Sobral, Joss Bland-Hawthorn, Julia J Bryant, Michael Goodwin, Jon S Lawrence, Nuria P F Lorente, Matt S Owers, The LEGA-C and SAMI galaxy surveys: quiescent stellar populations and the mass–size plane across 6 Gyr, Monthly Notices of the Royal Astronomical Society 2022 512, 3: 3828-3845 is available online at: https://academic.oup.com/mnras/article-abstract/512/3/3828/6549567

PY - 2022/5/31

Y1 - 2022/5/31

N2 - We investigate the change in mean stellar population age and metallicity ([Z/H]) scaling relations for quiescent galaxies from intermediate redshift ($0.60\leq z\leq0.76$) using the LEGA-C Survey, to low redshift ($0.014\leq z\leq0.10$) using the SAMI Galaxy Survey. We find that, similarly to their low-redshift counterparts, the stellar metallicity of quiescent galaxies at $0.60\leq z\leq 0.76$ closely correlates with $M_*/R_\mathrm{e}$ (a proxy for the gravitational potential or escape velocity), in that galaxies with deeper potential wells are more metal-rich. This supports the hypothesis that the relation arises due to the gravitational potential regulating the retention of metals, by determining the escape velocity required by metal-rich stellar and supernova ejecta to escape the system and avoid being recycled into later stellar generations. On the other hand, we find no correlation between stellar age and $M_*/R_\mathrm{e}^2$ (stellar mass surface density $\Sigma$) in the LEGA-C sample, despite this being a strong relation at low redshift. We consider this change in the age--$\Sigma$ relation in the context of the redshift evolution of the star-forming and quiescent populations in the mass--size plane, and find our results can be explained as a consequence of galaxies forming more compactly at higher redshifts, and remaining compact throughout their evolution. Furthermore, galaxies appear to quench at a characteristic surface density that decreases with decreasing redshift. The $z\sim 0$ age--$\Sigma$ relation is therefore a result of building up the quiescent and star-forming populations with galaxies that formed at a range of redshifts and so a range of surface densities.

AB - We investigate the change in mean stellar population age and metallicity ([Z/H]) scaling relations for quiescent galaxies from intermediate redshift ($0.60\leq z\leq0.76$) using the LEGA-C Survey, to low redshift ($0.014\leq z\leq0.10$) using the SAMI Galaxy Survey. We find that, similarly to their low-redshift counterparts, the stellar metallicity of quiescent galaxies at $0.60\leq z\leq 0.76$ closely correlates with $M_*/R_\mathrm{e}$ (a proxy for the gravitational potential or escape velocity), in that galaxies with deeper potential wells are more metal-rich. This supports the hypothesis that the relation arises due to the gravitational potential regulating the retention of metals, by determining the escape velocity required by metal-rich stellar and supernova ejecta to escape the system and avoid being recycled into later stellar generations. On the other hand, we find no correlation between stellar age and $M_*/R_\mathrm{e}^2$ (stellar mass surface density $\Sigma$) in the LEGA-C sample, despite this being a strong relation at low redshift. We consider this change in the age--$\Sigma$ relation in the context of the redshift evolution of the star-forming and quiescent populations in the mass--size plane, and find our results can be explained as a consequence of galaxies forming more compactly at higher redshifts, and remaining compact throughout their evolution. Furthermore, galaxies appear to quench at a characteristic surface density that decreases with decreasing redshift. The $z\sim 0$ age--$\Sigma$ relation is therefore a result of building up the quiescent and star-forming populations with galaxies that formed at a range of redshifts and so a range of surface densities.

KW - astro-ph.GA

KW - Galaxies: abundances

KW - Galaxies: evolution

KW - Galaxies: fundamental parameters

KW - Galaxies: statistics

KW - Galaxies: stellar content

KW - Galaxies: structure

U2 - 10.1093/mnras/stac705

DO - 10.1093/mnras/stac705

M3 - Journal article

VL - 512

SP - 3828

EP - 3845

JO - Monthly Notices of the Royal Astronomical Society

JF - Monthly Notices of the Royal Astronomical Society

SN - 0035-8711

IS - 3

ER -