A flat faint end of the Fornax cluster galaxy luminosity function

Abstract

We analyse the photometric properties of the early-type Fornax cluster dwarf galaxy population (M_V>-17 mag), based on a wide field imaging study of the central cluster area in V and I band-passes with IMACS/Magellan at Las Campanas Observatory. We create a fiducial sample of ~100 Fornax cluster dwarf ellipticals (dEs) with -16.6<M_V<-8.8 mag in the following three steps: (1) To verify cluster membership, we measured I-band surface brightness fluctuations (SBF) distances to candidate dEs known from previous surveys; (2) We re-assessed morphological classifications for those candidate dEs that are too faint for SBF detection; and (3) We searched for new candidate dEs in the size-luminosity regime close to the resolution limit of previous surveys. The resulting fiducial dE sample follows a well-defined surface brightness - magnitude relation, showing that Fornax dEs are about 40% larger than Local Group dEs. The sample also defines a colour-magnitude relation similar to that of Local Group dEs. The early-type dwarf galaxy luminosity function in Fornax has a very flat faint end slope alpha = -1.1 +/- 0.1. We compare the number of dwarfs per unit mass with those in other environments and find that the Fornax cluster fits well into a general trend of a lack of high-mass dwarfs in more massive environments.

arXiv comment5 pages, 4 figures, to appear in the proceedings of IAU Symposium 244 'Dark galaxies and lost baryons', Cambridge University Press, editors J. I. Davies & M. D. Disney

References in corpus (19)

• Dark Matter Substructure in Galactic Halos
• Mass function of dark matter halos
• A Unified Model for the Evolution of Galaxies and Quasars
• The Progenitors of Dwarf Spheroidal Galaxies
• The Formation of Giant Elliptical Galaxies and Their Globular Cluster Systems
• The SBF Survey of Galaxy Distances. II. Local and Large-Scale Flows
• A class of compact dwarf galaxies from disruptive processes in galaxy clusters
• Galaxy threshing and the origin of ultra-compact dwarf galaxies in the Fornax cluster
• The Build-up of the Colour-Magnitude Relation as a Function of Environment
• The faint end of the galaxy luminosity function
• The evolution and star formation of dwarf galaxies in the Fornax Cluster
• Spectroscopic metallicities for Fornax UCDs, GCs and dE,Ns
• The dwarf Low Surface Brightness galaxy population of the Virgo Cluster I. The faint-end-slope of the Luminosity Function
• A Photometric and Spectroscopic Study of Dwarf and Giant Galaxies in the Coma Cluster - IV. The Luminosity Function
• Galaxy Groups in the 2dFGRS: the number density of groups
• The Galaxy Luminosity Function from M_R = -25 to M_R = -9
• The Low Surface Brightness Extent of the Fornax Cluster
• New evidence for a linear colour-magnitude relation and a single Schechter function for red galaxies in a nearby cluster of galaxies down to M*+8
• Cluster mass functions in the quintessential Universe

Cited by in corpus (1)

• The HST/ACS Coma Cluster Survey: I - Survey Objectives and Design