Dwarf Spheroidal Galaxies

Abstract

Dwarf Spheroidal (dSph) galaxies are the faintest baryonic systems recognized as galaxies. Understanding the structure and stellar populations of these systems is critical for the modelling of their formation and evolution, and by extension, for understanding the general problem of galaxy formation and evolution. Further, as dSphs are the only available probes of the distant halo of the Galaxy, understanding their structure is a crucial step in the study of the gravitational potential of the halo and the mass of the Galaxy. I will not attempt to review fully all current topics of dSph research. Instead, I will concentrate specifically on those issues that are directly related (as I see it) to the overall topic of wide-field imaging. Recent reviews covering other aspects of dSph research have been written by DaCosta (1988, 1992) and Pryor (1992).