Giant shells and stellar arcs as relics of gamma-ray burst explosions

Gamma-ray burst (GRB) explosions are powerful and frequent enough to make kiloparsec-size shells and holes in the interstellar media of spiral and irregular galaxies. The observations of such remnants are summarized. Several observed shells contain no obvious central star clusters and could be GRB remnants, but sufficiently old clusters, which could have formed these shells by supernovae and winds, might be hard to detect.