The evolution of galaxies at constant number density: a less biased view of star formation, quenching, and structural formation
Due to significant galaxy contamination and impurity in stellar mass selected samples (up to 95 per cent from z = 0–3), we examine the star formation history, quenching time-scales, and structural evolution of galaxies using a constant number density selection with data from the United Kingdom Infra...
| Main Authors: | , , , , , , |
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| Format: | Article |
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Oxford University Press
2016
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| Online Access: | https://eprints.nottingham.ac.uk/39816/ |
| _version_ | 1848795919631253504 |
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| author | Ownsworth, Jamie R. Conselice, Christopher J. Mundy, Carl J. Mortlock, Alice Hartley, William G. Duncan, Kenneth Almaini, Omar |
| author_facet | Ownsworth, Jamie R. Conselice, Christopher J. Mundy, Carl J. Mortlock, Alice Hartley, William G. Duncan, Kenneth Almaini, Omar |
| author_sort | Ownsworth, Jamie R. |
| building | Nottingham Research Data Repository |
| collection | Online Access |
| description | Due to significant galaxy contamination and impurity in stellar mass selected samples (up to 95 per cent from z = 0–3), we examine the star formation history, quenching time-scales, and structural evolution of galaxies using a constant number density selection with data from the United Kingdom Infra-Red Deep Sky Survey Ultra-Deep Survey field. Using this methodology, we investigate the evolution of galaxies at a variety of number densities from z= 0–3. We find that samples chosen at number densities ranging from 3 × 10−4 to 10−5 galaxies Mpc−3 (corresponding to z ∼ 0.5 stellar masses of M∗ = 1010.95−11.6 M0) have a star-forming blue fraction of ∼50 per cent at z ∼ 2.5, which evolves to a nearly 100 per cent quenched red and dead population by z ∼ 1. We also see evidence for number density downsizing, such that the galaxies selected at the lowest densities (highest masses) become a homogeneous red population before those at higher number densities. Examining the evolution of the colours for these systems furthermore shows that the formation redshift of galaxies selected at these number densities is zform > 3. The structural evolution through size and S´ersic index fits reveal that while there remains evolution in terms of galaxies becoming larger and more concentrated in stellar mass at lower redshifts, the magnitude of the change is significantly smaller than for a mass-selected sample. We also find that changes in size and structure continues at z < 1, and is coupled strongly to passivity evolution.We conclude that galaxy structure is driving the quenching of galaxies, such that galaxies become concentrated before they become passive. |
| first_indexed | 2025-11-14T19:39:44Z |
| format | Article |
| id | nottingham-39816 |
| institution | University of Nottingham Malaysia Campus |
| institution_category | Local University |
| last_indexed | 2025-11-14T19:39:44Z |
| publishDate | 2016 |
| publisher | Oxford University Press |
| recordtype | eprints |
| repository_type | Digital Repository |
| spelling | nottingham-398162020-05-04T18:04:39Z https://eprints.nottingham.ac.uk/39816/ The evolution of galaxies at constant number density: a less biased view of star formation, quenching, and structural formation Ownsworth, Jamie R. Conselice, Christopher J. Mundy, Carl J. Mortlock, Alice Hartley, William G. Duncan, Kenneth Almaini, Omar Due to significant galaxy contamination and impurity in stellar mass selected samples (up to 95 per cent from z = 0–3), we examine the star formation history, quenching time-scales, and structural evolution of galaxies using a constant number density selection with data from the United Kingdom Infra-Red Deep Sky Survey Ultra-Deep Survey field. Using this methodology, we investigate the evolution of galaxies at a variety of number densities from z= 0–3. We find that samples chosen at number densities ranging from 3 × 10−4 to 10−5 galaxies Mpc−3 (corresponding to z ∼ 0.5 stellar masses of M∗ = 1010.95−11.6 M0) have a star-forming blue fraction of ∼50 per cent at z ∼ 2.5, which evolves to a nearly 100 per cent quenched red and dead population by z ∼ 1. We also see evidence for number density downsizing, such that the galaxies selected at the lowest densities (highest masses) become a homogeneous red population before those at higher number densities. Examining the evolution of the colours for these systems furthermore shows that the formation redshift of galaxies selected at these number densities is zform > 3. The structural evolution through size and S´ersic index fits reveal that while there remains evolution in terms of galaxies becoming larger and more concentrated in stellar mass at lower redshifts, the magnitude of the change is significantly smaller than for a mass-selected sample. We also find that changes in size and structure continues at z < 1, and is coupled strongly to passivity evolution.We conclude that galaxy structure is driving the quenching of galaxies, such that galaxies become concentrated before they become passive. Oxford University Press 2016-09-01 Article PeerReviewed Ownsworth, Jamie R., Conselice, Christopher J., Mundy, Carl J., Mortlock, Alice, Hartley, William G., Duncan, Kenneth and Almaini, Omar (2016) The evolution of galaxies at constant number density: a less biased view of star formation, quenching, and structural formation. Monthly Notices of the Royal Astronomical Society, 461 (1). pp. 1112-1129. ISSN 0035-8711 galaxies: evolution ; galaxies: fundamental parameters ; galaxies: high-redshift ; galaxies: structure http://mnras.oxfordjournals.org/content/461/1/1112 doi:10.1093/mnras/stw1207 doi:10.1093/mnras/stw1207 |
| spellingShingle | galaxies: evolution ; galaxies: fundamental parameters ; galaxies: high-redshift ; galaxies: structure Ownsworth, Jamie R. Conselice, Christopher J. Mundy, Carl J. Mortlock, Alice Hartley, William G. Duncan, Kenneth Almaini, Omar The evolution of galaxies at constant number density: a less biased view of star formation, quenching, and structural formation |
| title | The evolution of galaxies at constant number density: a less biased view of star formation, quenching, and structural formation |
| title_full | The evolution of galaxies at constant number density: a less biased view of star formation, quenching, and structural formation |
| title_fullStr | The evolution of galaxies at constant number density: a less biased view of star formation, quenching, and structural formation |
| title_full_unstemmed | The evolution of galaxies at constant number density: a less biased view of star formation, quenching, and structural formation |
| title_short | The evolution of galaxies at constant number density: a less biased view of star formation, quenching, and structural formation |
| title_sort | evolution of galaxies at constant number density: a less biased view of star formation, quenching, and structural formation |
| topic | galaxies: evolution ; galaxies: fundamental parameters ; galaxies: high-redshift ; galaxies: structure |
| url | https://eprints.nottingham.ac.uk/39816/ https://eprints.nottingham.ac.uk/39816/ https://eprints.nottingham.ac.uk/39816/ |