Gamma-ray burst host galaxies at low and high redshift

TL;DR

This paper reviews the properties of gamma-ray burst host galaxies across different redshifts, highlighting their typical low-mass, star-forming nature at low z and exploring their characteristics at high z, including metallicity and dust content.

Contribution

It provides a comparative analysis of GRB host galaxy properties at low and high redshifts, emphasizing recent findings on metallicity and dust in high-z hosts.

Findings

Low-z GRB hosts are similar to general star-forming galaxies.

Some high-z GRB hosts are associated with dusty, massive galaxies.

A super-solar metallicity was measured in a z=3.57 GRB host.

Abstract

The galaxies hosting the most energetic explosions in the universe, the gamma-ray bursts (GRBs), are generally found to be low-mass, metal poor, blue and star forming galaxies. However, the majority of the targets investigated so far (less than 100) are at relatively low redshift, z < 2. We know that at low redshift, the cosmic star formation is predominantly in small galaxies. Therefore, at low redshift, long-duration GRBs, which are associated with massive stars, are expected to be in small galaxies. Preliminary investigations of the stellar mass function of z < 1.5 GRB hosts does not indicate that these galaxies are different from the general population of nearby star-forming galaxies. At high-z, it is still unclear whether GRB hosts are different. Recent results indicate that a fraction of them might be associated with dusty regions in massive galaxies. Remarkable is the a super-solar metallicity measured in the interstellar medium of a z = 3.57 GRB host.