1112.0029 (Fabio Fontanot et al.)

On the Evolution of the Star Formation Rate Function of Massive Galaxies. Constraints at 0.4    [PDF]

Fabio Fontanot, Stefano Cristiani, Paola Santini, Adriano Fontana, Andrea Grazian, Rachel S. Somerville

[abridged] We study the evolution of the Star Formation Rate Function (SFRF) of massive galaxies over the 0.41.e10 Msun range and determine the SFRF using the 1/Vmax algorithm. We define simulated galaxy catalogues based on three different semi-analytical models of galaxy formation and evolution. We show that the theoretical SFRFs are well described by a double power law functional form and its redshift evolution is approximated with high accuracy by a pure evolution of the typical SFR. We find good agreement between model predictions and the high-SFR end of the SFRF, when the observational errors on the SFR are taken into account. However, the observational SFRF is characterised by a double peaked structure, which is absent in its theoretical counterparts. At z>1.0 the observed SFRF shows a relevant density evolution, which is not reproduced by SAMs, due to the well known overprediction of intermediate mass galaxies at z~2. The agreement at the low-SFR end is poor: all models overpredict the space density of SFR~1 Msun/yr and no model reproduces the double peaked shape of the observational SFRF. If confirmed by deeper IR observations, this discrepancy will provide a key constraint on theoretical modelling of star formation and stellar feedback.

View original: http://arxiv.org/abs/1112.0029