Abstract
We compile and homogenize local galaxy samples with available information on morphology, and stellar, HI and/or H2 masses. After taking into account non gas detections, we determine the HI- and H2-to-stellar mass relations and their 1σ scatter for late- and early-type galaxies. These relations are fitted to single or double power laws. Late-type galaxies are significantly gas richer than early-type ones, especially at high masses. The H2-to-HI mass ratios as a function of M* are discussed. We constrain the distribution functions of the HI- and H2-to-stellar mass ratios. We find that they can be described by a Schechter function for late types and a (broken) Schechter + uniform function for early types. Using the observed galaxy stellar mass function and the volumecomplete late-to-early-type galaxy ratio as a function of M*, these distributions are mapped into HI and H2 mass functions. The mass functions are consistent with those inferred from large surveys. The results presented here can be used to constrain models and simulations of galaxy evolution.
