The evolution of field early-type galaxies to z~0.7
Abstract
We have measured the Fundamental Plane (FP) parameters for a sample of 30 field early-type galaxies (E/S0) in the redshift range 0.1<z<0.66. We find that: i) the FP is defined and tight out to the highest redshift bin; ii) the intercept \gamma evolves as d\gamma/dz=0.58+0.09-0.13 (for \Omega=0.3, \Omega_{\Lambda}=0.7), or, in terms of average effective mass to light ratio, as d\log(M/L_B)/dz=-0.72+0.11-0.16, i.e. faster than is observed for cluster E/S0 -0.49+-0.05. In addition, we detect [OII] emission >5\AA in 22% of an enlarged sample of 42 massive E/S0 in the range 0.1<z<0.73, in contrast with the quiescent population observed in clusters at similar z. We interpret these findings as evidence that a significant fraction of massive field E/S0 experiences secondary episodes of star-formation at z<1.
Cite
@article{arxiv.astro-ph/0111504,
title = {The evolution of field early-type galaxies to z~0.7},
author = {T. Treu and M. Stiavelli and S. Casertano and P. Møller and G. Bertin},
journal= {arXiv preprint arXiv:astro-ph/0111504},
year = {2014}
}
Comments
ApJ Letters, in press