1. Massive post-starburst galaxies at z > 1 are compact proto-spheroids
- Author
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William G. Hartley, Nina A. Hatch, Ross J. McLure, David T. Maltby, Vivienne Wild, Omar Almaini, Kate Rowlands, James Dunlop, Chris Simpson, European Research Council, and University of St Andrews. School of Physics and Astronomy
- Subjects
Radio galaxy ,structure [Galaxies] ,Astrophysics ,Astrophysics::Cosmology and Extragalactic Astrophysics ,01 natural sciences ,Peculiar galaxy ,high-redshift [Galaxies] ,galaxies: high-redshift ,Galaxy group ,0103 physical sciences ,QB Astronomy ,Astrophysics::Solar and Stellar Astrophysics ,galaxies: formation ,Disc ,Brightest cluster galaxy ,010303 astronomy & astrophysics ,Lenticular galaxy ,evolution ,galaxies: fundamental parameters ,galaxies: structure [galaxies] ,QC ,Astrophysics::Galaxy Astrophysics ,QB ,Luminous infrared galaxy ,Physics ,fundamental paramaters [Galaxies] ,010308 nuclear & particles physics ,Astronomy ,Astronomy and Astrophysics ,3rd-DAS ,evolution [Galaxies] ,formation [Galaxies] ,Astrophysics - Astrophysics of Galaxies ,QC Physics ,Space and Planetary Science ,Elliptical galaxy ,galaxies: structure ,galaxies: evolution ,galaxies: evolution – galaxies: formation – galaxies: fundamental parameters – galaxies: structure – galaxies: high-redshift - Abstract
We investigate the relationship between the quenching of star formation and the structural transformation of massive galaxies, using a large sample of photometrically selected post-starburst galaxies in the UKIDSS Ultra-Deep Survey field. We find that post-starburst galaxies at high redshift (z > 1) show high Sérsic indices, significantly higher than those of active star-forming galaxies, but with a distribution that is indistinguishable from the old quiescent population. We conclude that the morphological transformation occurs before (or during) the quenching of star formation. Recently quenched galaxies are also the most compact; we find evidence that massive post-starburst galaxies (M* > 1010.5 M⊙) at high redshift (z > 1) are on average smaller than comparable quiescent galaxies at the same epoch. Our findings are consistent with a scenario in which massive passive galaxies are formed from three distinct phases: (1) gas-rich dissipative collapse to very high densities, forming the proto-spheroid, (2) rapid quenching of star formation to create the ‘red nugget’ with post-starburst features and (3) a gradual growth in size as the population ages, perhaps as a result of minor mergers., Monthly Notices of the Royal Astronomical Society, 472 (2), ISSN:0035-8711, ISSN:1365-2966, ISSN:1365-8711
- Published
- 2017
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