GRB host studies (GHostS)

The GRB Host Studies (GHostS) is a public archive collecting observed quantities of GRB host galaxies. At this time (January 2006) it contains information on 32 GRB hosts, i.e. about half of the total number of GRBs with known redshift. Here we present some preliminary statistical analysis of the sample, e.g. the total stellar mass, metallicity and star formation rate for the hosts. We found that these are generally low-mass objects, with 79% having M* < 1010 M⊙. The total stellar mass and the metallicity for a subsample of 7 hosts at 0.4 < z < 1 are consistent with the mass-metallicity relation recently found for normal star-forming galaxies in the same redshift interval. At least 56% of the total sample are bursty galaxies: their growth time-scale (the time required to form the observed stellar mass assuming that the observed SFR is constant over the entire life of the galaxy) is shorter than 400 Myr. © 2006 American Institute of Physics.