Identification and Properties of Isolated Field Elliptical Galaxies from CFHTLS-W1

TL;DR

This study presents a catalog of isolated elliptical galaxies from CFHTLS-W1, comparing their properties with those in dense environments, revealing similar behaviors in key characteristics and scaling relations.

Contribution

The paper provides the first uniform catalog of isolated field elliptical galaxies from CFHTLS-W1 and compares their properties with cluster ellipticals using the same dataset.

Findings

Isolated ellipticals and brightest cluster galaxies have similar colors and star formation activities.

Both types follow similar mass-size and size-luminosity relations.

Some isolated ellipticals are associated with fossil groups, indicating potential evolutionary links.

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 $-24 \leq M_{r} \leq -22$ magnitude and $10.2< \textrm{log}( \textrm M_{*}/ \textrm M_\odot)\leq12.0$ 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.