Star formation in low-redshift cluster dwarf galaxies
  Evolution of galaxies in dense environments can be affected by close
encounters with neighbouring galaxies and interactions with the intracluster
medium. Dwarf galaxies (dGs) are important as their low mass makes them more
susceptible to these effects than giant systems. Combined luminosity functions
(LFs) in the r- and u-band of 15 galaxy clusters were constructed using
archival data from the Canada-France-Hawaii Telescope. LFs were measured as a
function of cluster-centric radius from stacked cluster data. Marginal evidence
was found for an increase in the faint-end slope of the u-band LF relative to
the r-band with increasing cluster-centric radius. The dwarf-to-giant ratio
(DGR) was found to increase toward the cluster outskirts, with the u-band DGR
increasing faster with cluster-centric radius compared to the r-band. The dG
blue fraction was found to be ~2 times larger than the giant galaxy blue
fraction over all cluster-centric distance (~5sigma level). The central
concentration (C) was used as a proxy to distinguish nucleated versus
non-nucleated dGs. The ratio of high-C to low-C dGs was found to be ~2 times
greater in the inner cluster region compared to the outskirts (2.8sigma level).
The faint-end slope of the r-band LF for the cluster outskirts (0.6 < r/r_200 <
1.0) is steeper than the SDSS field LF, while the u-band LF is marginally
steeper at the 2.5sigma level. Decrease in the faint-end slope of the r- and
u-band cluster LFs towards the cluster centre is consistent with quenching of
star formation via ram pressure stripping and galaxy-galaxy interactions.
