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