Friday, 14 March 2008

arXiv:0803.1489 [ps, pdf, other]
Title: The contribution of star formation and merging to stellar mass buildup in galaxies
Authors: Niv Drory (1), Marcelo Alvarez (2) ((1) MPE, Garching, Germany, (2) KIPAC-Stanford, USA)
Comments: Accepted for publication in ApJ
Subjects: Astrophysics (astro-ph)
The authors take data from the FORS Deep Field (FDF), 5500 galaxies with redshifts between 0 and 5. They obtain stellar masses and SFRs as well as photo-z's. By integrating the SFR over time they calculate, as a function of mass, the change in number density of galaxies of that mass due to star formation. They compare that to the actual change of the mass function to obtain the contribution that is from anything other than star formation, being mainly merging and accretion (assuming that tidal stripping and so on are negligable). They call this the assembly rate and that is what is shown in the figure (the y-axis normalized to have the relative change), as a function of z and mass (in both plots). See the paper for selection effects...

No comments: