Star formation rates of blue compact galaxies

Using Halpha, [OII]3727, infrared (IR), radio (1.4GHz) luminosities and neutral hydrogen (HI) gas masses, we estimated star formation rates and gas depletion timescales of 72 star-forming blue compact galaxies (BCGs) To assess the possible systematic differences among different star formation rate indicators, we compared the star formation rates derived from Halpha, [OII]3727, IR, and radio luminosities, and investigated the effects from underlying stellar absorption and dust extinction.

We found that subtracting underlying stellar absorption is very important to calculate both dust extinction and star formation rate of galaxies. Otherwise, the intrinsic extinction will be overestimated, the star formation rates derived from [OII]3727 and Halpha will be underestimated (if the underlying stellar absorption and the internal extinction were not corrected from the observed luminosity) or overestimated (if an overestimated internal extinction were used for extinction correction).