The z=0 Galaxy Luminosity Function: I. Techniques for Identification of Dwarf Galaxies at ~10 Mpc

Abstract

We present a program to study the galaxy luminosity function (GLF) of the Leo I and Coma I Groups at ~10 Mpc. We have surveyed over seven square degrees in Leo I and ~11 square degrees in Coma I. In this paper, we detail the method we have developed and implemented for identifying on morphological grounds low-surface-brightness, M_R < -10 dwarf galaxies at a distance of 10 Mpc. We also describe extensive Montecarlo simulations of artificial galaxies which we use to tune our detection algorithms and evaluate our detection efficiency and parameter recovery as a function of mu_R(0) and R_T. We find for a sub-set of our Leo I data that at the 90% completeness level we can detect dwarfs comparable to Antlia and Sculptor. Finally, we describe preliminary follow-up observations which confirm we are detecting dwarf spheroidals in Leo I at 10 Mpc.

14 pages, 22 figures, accepted for publication in ApJS, for eps versions of figures, see http://www.ucolick.org/~flint/GLF/Paper1/