Galaxy environments in the UKIDSS Ultra Deep Survey

R. W. Chuter, O. Almaini, W. G. Hartley, R. J. McLure, J. S. Dunlop, S. Foucaud, C. J. Conselice, C. Simpson, M. Cirasuolo, E. J. Bradshaw

Research output: Contribution to journalArticlepeer-review

Abstract

We present a study of galaxy environments to z similar to 2, based on a sample of over 33 000 K-band-selected galaxies detected in the UKIDSS Ultra Deep Survey (UDS). The combination of infrared depth and area in the UDS allows us to extend previous studies of galaxy environment to z > 1 without the strong biases associated with optical galaxy selection. We study the environments of galaxies divided by rest-frame (U - B) colours, in addition to 'passive' and 'star-forming' subsets based on template fitting. We find that galaxy colour is strongly correlated with galaxy overdensity on small scales (< 1-Mpc diameter), with red/passive galaxies residing in significantly denser environments than blue/star-forming galaxies to z similar to 1.5. On smaller scales (< 0.5-Mpc diameter) we also find a relationship between galaxy luminosity and environment, with the most luminous blue galaxies at z similar to 1 inhabiting environments comparable to red, passive systems at the same redshift. Monte Carlo simulations demonstrate that these conclusions are robust to the uncertainties introduced by photometric redshift errors.

Original languageEnglish
Pages (from-to)1678-1686
Number of pages9
JournalMonthly Notices of the Royal Astronomical Society
Volume413
Issue number3
DOIs
Publication statusPublished - May 2011

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