The Evolution of Baryonic Mass Function of Galaxies to z = 3

Abstract

We combine the published stellar mass function (SMF) and gas scaling relations to explore the baryonic (stellar plus cold gas) mass function (BMF) of galaxies to redshift z  = 3. We find evidence that at log( M baryon / M ☉ ) > 11.3, the BMF has evolved little since z  ∼ 2.2. With the evolution of BMF and SMF, we investigate the baryon net accretion rate ( ) and stellar mass growth rate ( ) for the galaxy population of log( M star / M ☉ ) > 10. The ratio between these two quantities, / , decreases from / at z  ∼ 2.5 to / at z  ∼ 0.5, suggesting that massive galaxies are transforming from the “accretion-dominated” phase to the “depletion-dominated” phase from high- z to low- z . The transition of these two phases occurs at z  ∼ 1.5, which is consistent with the onset redshift of the decline of cosmic star formation rate density (CSFD). This provides evidence to support the idea that the decline of CSFD since z  ∼ 1.5 mainly results from the decline of baryon net accretion rate and star formation quenching in galaxies.