Star-formation histories of blue compact dwarf galaxies

Abstract

We present the results of a multi-wavelength observational study of actively star-forming dwarf galaxies (also known as Blue Compact Dwarfs). We combine optical, infrared and H-alpha imaging with optical spectroscopy and HI data in an attempt to better understand the stellar population make-up and star-formation histories of this type of galaxy. In particular, we address the long-standing ambiguity concerning the source of the near-infrared flux in BCDs. We find in nearly all cases that there is clear evidence for an older population of stars. However, the currently active starburst often contributes a large fraction of the total near-infrared flux in the form of nebular continuum emission and/or light from hot main sequence stars.