Environment and the epochs of galaxy formation in the SDSS era

D. Thomas, C. Maraston, K. Schawinski, M. Sarzi, S. J. Joo, S. Kaviraj, Sukyoung Yi

Research output: Contribution to journalArticle

1 Citation (Scopus)

Abstract

We analyse a sample of 1,652 elliptical galaxies morphologically selected from the SDSS DR4 with respect to their stellar population properties such as luminosity weighted ages, metallicities and /Fe element abundance ratios. We confirm and statistically strengthen earlier results that all three stellar population parameters correlate with velocity dispersion, hence galaxy mass. Most surprisingly and differently from previous work, however, these scaling relations turn out to be independent of environmental density for the bulk of the population. This implies that the formation epochs and timescales of the stellar populations in massive galaxies are entirely independent of the environmental density and only driven by galaxy mass. At the low-mass end some fraction of the galaxies show signs of recent star formation on top of the general downsizing trend. It is only the fractional amount of such rejuvenated galaxies that reveals strong dependence with environment. The influence of the environment apparently undergoes a phase transition at about z 1. An early galaxy formation phase without environmental dependence is followed by a rejuvenation phase at redshifts below z 1 affecting mostly low-mass galaxies, during which the environment plays a crucial role.

Original languageEnglish
Pages (from-to)546-550
Number of pages5
JournalProceedings of the International Astronomical Union
Volume2
Issue numberS241
DOIs
Publication statusPublished - 2006 Dec 1

Fingerprint

Galaxies
galactic evolution
time measurement
galaxies
phase transition
elliptical galaxies
timescale
metallicity
star formation
luminosity
Stars
trends
scaling
Luminance
Phase transitions

All Science Journal Classification (ASJC) codes

  • Physics and Astronomy (miscellaneous)
  • Aerospace Engineering

Cite this

Thomas, D. ; Maraston, C. ; Schawinski, K. ; Sarzi, M. ; Joo, S. J. ; Kaviraj, S. ; Yi, Sukyoung. / Environment and the epochs of galaxy formation in the SDSS era. In: Proceedings of the International Astronomical Union. 2006 ; Vol. 2, No. S241. pp. 546-550.
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Thomas, D, Maraston, C, Schawinski, K, Sarzi, M, Joo, SJ, Kaviraj, S & Yi, S 2006, 'Environment and the epochs of galaxy formation in the SDSS era', Proceedings of the International Astronomical Union, vol. 2, no. S241, pp. 546-550. https://doi.org/10.1017/S1743921307009088

Environment and the epochs of galaxy formation in the SDSS era. / Thomas, D.; Maraston, C.; Schawinski, K.; Sarzi, M.; Joo, S. J.; Kaviraj, S.; Yi, Sukyoung.

In: Proceedings of the International Astronomical Union, Vol. 2, No. S241, 01.12.2006, p. 546-550.

Research output: Contribution to journalArticle

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AU - Sarzi, M.

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AU - Kaviraj, S.

AU - Yi, Sukyoung

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