Poster Presentation Astronomical Society of Australia Annual Scientific Meeting including HWWS 2013

Using Scaling Relations to Examine the Effects of Environment on High Redshift Galaxy Evolution (#204)

Rebecca Allen 1 , Glenn Kacprzak 1 , Karl Glazebrook 1 , Lee Spitler 2
  1. Swinburne University, Hawthorn, Vic, Australia
  2. Macquarie University, North Ryde, NSW, Australia

The galaxy size-mass relation is a key tool used to confirm galaxy formation and evolution scenarios and can be further implemented to address the role of environment. Disagreement exists regarding the extent to which environment affects galaxy evolution at redshifts above z~1. Using the Z-FOURGE medium-band survey we selected a sample of ~40 cluster and ~300 field galaxies having photometric redshifts between 2<z<2.2. We then stacked the publicly available HST galaxy images in order to accurately measure the typical light profiles of cluster and field galaxies. We directly compared the radial surface brightness profiles, sizes, and Sérsic indices of the field and cluster galaxies in different environments. We find that high mass (1010<(M/Mʘ)<1011) cluster galaxies are larger and less compact than their field counterparts while low mass galaxies (109<(M/Mʘ)<1010) in both environments appear to be similar.  This implies that higher mass cluster galaxies are evolving at an accelerated rate compared to galaxies in the field and that minor mergers could be the driver of this rapid growth.