GEMS: The Size Evolution of Disk Galaxies
Abstract
We combine HST imaging from the GEMS survey with photometric redshifts from COMBO-17 to explore the evolution of disk-dominated galaxies since z<1.1. The sample is comprised of all GEMS galaxies with Sersic indices n<2.5, derived from fits to the galaxy images. We account fully for selection effects through careful analysis of image simulations; we are limited by the depth of the redshift and HST data to the study of galaxies with absolute magnitudes M(V)<-20, or equivalently stellar masses log(M)>10. We find strong evolution in the magnitude-size scaling relation for galaxies with M(V)<-20, corresponding to a brightening of 1 mag per sqarcsec in rest-frame V-band by z=1. Yet, disks at a given absolute magnitude are bluer and have lower stellar mass-to-light ratios at z=1 than at the present day. As a result, our findings indicate weak or no evolution in the relation between stellar mass and effective disk size for galaxies with log(M)>10 over the same time interval. This is strongly inconsistent with the most naive theoretical expectation, in which disk size scales in proportion to the halo virial radius, which would predict that disks are a factor of two denser at fixed mass at z=1. The lack of evolution in the stellar mass-size relation is consistent with an ``inside-out'' growth of galaxy disks on average (galaxies increasing in size as they grow more massive), although we cannot rule out more complex evolutionary scenarios.
Cite
@article{arxiv.astro-ph/0502416,
title = {GEMS: The Size Evolution of Disk Galaxies},
author = {Marco Barden and Hans-Walter Rix and Rachel S. Somerville and Eric F. Bell and Boris Haeussler and Chien Y. Peng and Andrea Borch and Steven V. W. Beckwith and John A. R. Caldwell and Catherine Heymans and Knud Jahnke and Shardha Jogee and Daniel H. McIntosh and Klaus Meisenheimer and Sebastian F. Sanchez and Lutz Wisotzki and Christian Wolf},
journal= {arXiv preprint arXiv:astro-ph/0502416},
year = {2015}
}
Comments
22 pages, 16 figures, submitted to ApJ