Star Formation Histories of Nearby Dwarf Galaxies

Abstract

Properties of nearby dwarf galaxies are briefly discussed. Dwarf galaxies vary widely in their star formation histories, the ages of their subpopulations, and in their enrichment history. Furthermore, many dwarf galaxies show evidence for spatial variations in their star formation history; often in the form of very extended old populations and radial gradients in age and metallicity. Determining factors in dwarf galaxy evolution appear to be both galaxy mass and environment. We may be observing continuous evolution from low-mass dwarf irregulars via transition types to dwarf spheroidals, whereas other evolutionary transitions seem less likely.