The Project

GRB Host Studies (GHostS) is a database dedicated to the properties of galaxies hosting gamma-ray bursts, a.k.a. GRB hosts.

Gamma-ray bursts (GRBs) are the most energetic events in the universe, second only to the Big Bang. Discovered in the late 1960s, their cosmological origin was revealed only in 1997, when the first distance (redshift) of a GRB was determined. This was GRB 970508 at redshift z = 0.835, exploded when the universe was about half of its present age.

Since then, the redshift was measured for just over 200 GRBs (Jan 2010), although on average a few events a day can in principle be detected by satellites. The difficulty of determining the distance is connected to the fast fading of the blast, which generally disappears in a few days.

Primarily, our project focuses on estimating the stellar mass, rate of star formation and chemical enrichment of GRB hosts, as well as the evolution of these parameters over cosmic time, and their differences with normal galaxies.

In previous studies, it has been found that GRB hosts are typically low massive galaxies forming stars at a high rate. Their relatively low chemical enrichment reveals their young age. Samples under analysis are generally very small, due to the difficulty in acquiring data for faint objects. Whether metal rich, high mass and more quiescent GRB hosts are rare or just hard to find is not clear yet.

At the moment GHostS contains information about half of all GRBs with known redshift. More data will be included in the database as they become public.

Acknowledging Us

Please acknowledge the use of the GHostS database in astronomy publications as follows: "This research has made use of the GHostS database (, which is partly funded by Spitzer/NASA grant RSA Agreement No. 1287913."

GHostS Team

  • Sandra Savaglio (PI)
  • Karl Glazebrook
  • Damien Le Borgne
  • László Dobos
  • Tamás Budavári