Galaxy Luminosity Functions from Deep Spectroscopic Samples of Rich Clusters

Astrophysics, abstract
astro-ph/0304031

From: Daniel Christlein <dchristl@hotspur.as.arizona.edu>

Date: Tue, 1 Apr 2003 20:21:36 GMT   (105kb)

Authors:
Daniel Christlein,
Ann Zabludoff (Steward Observatory, The University of Arizona)

Comments: 53 pages, 8 figures, 1 ASCII table; accepted for publication in ApJ

Using a new spectroscopic sample and methods accounting for spectroscopic
sampling fractions that vary in magnitude and surface brightness, we present
R-band galaxy luminosity functions (GLFs) for six nearby galaxy clusters with
redshifts 4000 < cz < 20000 km/s and velocity dispersions 700 < sigma < 1250
km/s. In the case of the nearest cluster, Abell 1060, our sample extends to
M_R=-14 (7 magnitudes below M*), making this the deepest spectroscopic
determination of the cluster GLF to date. Our methods also yield composite GLFs
for cluster and field galaxies to M_R=-17 (M*+4), including the GLFs of
subsamples of star forming and quiescent galaxies. The composite GLFs are
consistent with Schechter functions (M*_R=-21.14^{+0.17}_{-0.17},
alpha=-1.21^{+0.08}_{-0.07} for the clusters, M*_R=-21.15^{+0.16}_{-0.16},
alpha=-1.28^{+0.12}_{-0.11} for the field). All six cluster samples are
individually consistent with the composite GLF down to their respective
absolute magnitude limits, but the GLF of the quiescent population in clusters
is not universal. There are also significant variations in the GLF of quiescent
galaxies between the field and clusters that can be described as a steepening
of the faint end slope. The overall GLF in clusters is consistent with that of
field galaxies, except for the most luminous tip, which is enhanced in clusters
versus the field. The star formation properties of giant galaxies are more
strongly correlated with the environment than those of fainter galaxies.

References and citations for this submission:

SLAC-SPIRES HEP (refers to ,
cited by, arXiv reformatted)