Star Formation in Massive Low Surface Brightness Galaxies

Massive low surface brightness galaxies have disk central surface brightnesses at least one magnitude fainter than the night sky, but total magnitudes and masses that show they are among the largest galaxies known. Like all low surface brightness (LSB) galaxies, massive LSB galaxies are often in the midst of star formation yet their stellar light has remained diffuse, raising the question of how star formation is proceeding within these systems. HI observations have played a crucial role in studying LSB galaxies as they are typically extremely gas rich. In the past few years we have more than quadrupled the total number of massive LSB galaxies, primarily through HI surveys. To clarify their structural parameters and stellar and gas content, we have undertaken a multi-wavelength study of these enigmatic systems. The results of this study, which includes HI, CO, optical, near UV, and far UV images of the galaxies, will provide the most in depth study done to date of how, when, and where star formation proceeds within this unique subset of the galaxy population.