Speaker: Nic Bonne

Galaxy luminosity functions are used to measure the distribution of galaxy masses and star formation rates, and are thus critical for measuring galaxy growth and for constraining galaxy formation models. Though functions have been measured in many wavelengths, very little research has focused on what actually shapes the galaxy luminosity function, and as a result, many functions are fitted empirically rather than with physically motivated functional forms. To address this issue, we have measured luminosity functions which trace galaxy stellar mass, as well as functions which trace current star formation, as functions of galaxy morphology and of galaxy optical colour. As dark matter halo mass and stellar mass have a strong correlation, we show that functions of the two share a similar form. Star formation does not have such a clear correlation, and we propose a new method for fitting star forming luminosity functions by convolving models of the star formation rate duty cycle with functions of stellar mass.