gamma-ray bursts

Gamma-ray bursts from stellar remnants: probing the Universe at high redshift

A gamma-ray burst (GRB) releases an amount of energy similar to that of a supernova explosion, which combined with its rapid variability suggests an origin related to neutron stars or black holes. Since these compact stellar remnants form from the …

Using STIS to find gamma-ray burst redshifts

A recent spectrum of the optical afterglow of GRB 970508 suggests that gamma-ray bursts (GRBs) are cosmological in origin, and it is of crucial importance to derive an accurate distance to each burst. If GRBs occur near their host galaxies …

The decay of optical emission from the γ-ray burst GRB 970228.

The optical counterpart of the γ-ray burst GRB 970228 appears to be a transient point source embedded in a region of extended nebulosity, the latter having been tentatively identified as a high-redshift galaxy. This would seem to favour models that …

The corrected log N-log fluence distribution of cosmological γ-ray bursts

Recent analysis of relativistically expanding shells of cosmological γ-ray bursts has shown that if the bursts are cosmological, then most likely total energy (E$_0$) is standard and not peak luminosity (L$_0$). Assuming a flat Friedmann cosmology …

The corrected log N-log fluence distribution of cosmological γ-ray bursts

Recent analysis of relativistically expanding shells of cosmological γ-ray bursts has shown that if the bursts are cosmological, then most likely total energy (E$_0$) is standard and not peak luminosity (L$_0$). Assuming a flat Friedmann cosmology …