On the Upper Limit of Surface Brightness of Starburst Galaxies

Abstract

We discuss the possible physical basis for a limiting surface brightness for starburst galaxies. Using basic models for star formation and the interstellar medium, we examine various process that might disrupt the interstellar medium including: radiation driven outflows with opacities given by Thomson scatter-ing, and dust; supernovae driven outflows; cooling processes; and the photodis-sociation of molecular clouds in the intense radiation field. We find that these processes can roughly explain the observed upper limit although a detailed fit is not yet achievable. We generalize our results to spherical systems and find that luminosity density is a fundamental parameter.