The Detailed Fundamental Plane of Two High-Redshift Clusters: MS 2053-04 at z=0.58 and MS 1054-03 at z=0.83

Abstract

We study the fundamental plane relation in high-redshift clusters using a sample of 26 galaxies in MS 2053-04 (z=0.583) and 22 galaxies in MS 1054-03 (z=0.83). The zero point and scatter are compared to results for lower redshift clusters in order to trace evolutionary effects. Furthermore, our large sample enables us to investigate correlations between residuals from the fundamental plane and other characteristics of the galaxies, such as color, Hβ line strength, spatial distribution, and mass. The observed scatter of the early-type galaxies with σ>100 km s^-1 around the fundamental plane is 0.134 and 0.106 in logr_e for MS 2053-04 and MS 1054-03, respectively. The residuals from the fundamental plane of MS 2053-04 are correlated with residuals from the Hβ-σ relation, suggesting that stellar populations are playing a role in shaping the fundamental plane. The measured evolution in logM/L is influenced by selection effects, as galaxies with lower M/L in the Johnson B-band enter a magnitude-limited sample more easily. When we select high-mass early-type galaxies to avoid this bias, we find logM/L_B~-0.47z and a formation redshift z_form~2.95, similar to earlier results.