We have developed a simple, static model designed to place a very solid lower limit on the star formation rate (SFR) expected in a dwarf disk galaxy, which leads to the prediction of a previously undocumented relation between HI mass, M_HI, and SFR. Over the mass range 10^8--10^10 M_sun, a wide variety of galaxies are observed to follow such a relation -- SFR ~ M_HI^1.4 -- with the same slope and similar scatter to our prediction. Within the model, this relation is a manifestation of self-regulating star formation (SF), in which the ISM is kept warm and stable by a UV interstellar radiation field (ISRF) that is maintained by constant regeneration of O--B stars. Regardless of the actual mode of star formation, it seems that the majority of dwarfs are presently forming stars in the same way.
Categories: astro-ph