Identification and properties of isolated field elliptical galaxies from CFHTLS-W1

Abstract

We present a catalogue of isolated field elliptical (IfE) galaxies drawn from the W1 field of the Canada-France-Hawaii Telescope Legacy Survey (CFHTLS). 228 IfEs were identified from a flux-limited (r<21.8) galaxy catalogue which corresponds to a density of 3 IfE/sq.deg. For comparison we consider a sample of elliptical galaxies living in dense environments, based on identification of the brightest cluster galaxies (BGCs) in the same survey. Using the same dataset for the comparison sample ensures a uniform selection, including in the redshift range as IfEs (i.e. 0.1 < z < 0.9). A comparison of elliptical galaxies in different environments reveals that IfEs and BCGs have similar behaviours in their colours, star formation activities, and scaling relations of mass-size and size-luminosity. IfEs and BCGs have similar slopes in the scaling relations with respect to cluster ellipticals within the -24 <= M-r <= -22 magnitude and 10.2< log(M-*/ M-circle dot) <= 12.0 mass ranges. Three IfEs identified in this study can be associated with fossil groups found in the same survey area which gives clues for future studies.