Galaxy sizes as a function of environment at intermediate redshift from the ESO Distant Cluster Survey

Kshitija Kelkar, Alfonso KelkarAragón-Salamanca, Meghan E. Gray, David Maltby, Benedetta Vulcani, Gabriella De Lucia, Bianca M. Poggianti, Dennis Zaritsky

Research output: Contribution to journalArticle

20 Scopus citations

Abstract

In order to assess whether the environment has a significant effect on galaxy sizes, we compare the mass-size relations of cluster and field galaxies in the 0.4 < z < 0.8 redshift range from the ESO Distant Cluster Survey (EDisCS) using Hubble Space Telescope images. We analyse two mass-selected samples, one defined using photometric redshifts (10.2 ≤ log M*/M ≤ 12.0), and a smaller more robust subsample using spectroscopic redshifts (10.6 ≤ log M*/M ≤ 11.8). We find no significant difference in the size distributions of cluster and field galaxies of a given morphology. Similarly, we find no significant difference in the size distributions of cluster and field galaxies of similar rest-frame B - V colours. We rule out average size differences larger than 10-20 per cent in both cases. Consistent conclusions are found with the spectroscopic and photometric samples. These results have important consequences for the physical process(es) responsible for the size evolution of galaxies, and in particular the effect of the environment. The remarkable growth in galaxy size observed from z ~ 2.5 has been reported to depend on the environment at higher redshifts (z > 1), with early-type/passive galaxies in higher density environments growing earlier. Such dependence disappears at lower redshifts. Therefore, if the reported difference at higher-z is real, the growth of field galaxies has caught up with that of cluster galaxies by z ~ 1. Any putative mechanism responsible for galaxy growth has to account for the existence of environmental differences at high redshift and their absence (or weakening) at lower redshifts.

Original languageEnglish (US)
Pages (from-to)1246-1255
Number of pages10
JournalMonthly Notices of the Royal Astronomical Society
Volume450
Issue number2
DOIs
StatePublished - Apr 10 2015

Keywords

  • Galaxies: clusters: general
  • Galaxies: elliptical and lenticular, cD
  • Galaxies: evolution
  • Galaxies: fundamental parameters
  • Galaxies: spiral
  • Galaxies: statistics

ASJC Scopus subject areas

  • Astronomy and Astrophysics
  • Space and Planetary Science

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    Kelkar, K., KelkarAragón-Salamanca, A., Gray, M. E., Maltby, D., Vulcani, B., De Lucia, G., Poggianti, B. M., & Zaritsky, D. (2015). Galaxy sizes as a function of environment at intermediate redshift from the ESO Distant Cluster Survey. Monthly Notices of the Royal Astronomical Society, 450(2), 1246-1255. https://doi.org/10.1093/mnras/stv670