# intergalactic medium

## Casting Light on the Anomalous'' Statistics of Mg II Absorbers Toward Gamma-ray Burst Afterglows: The Incidence of Weak Systems

We revisit echelle spectra (spectral resolution R ≈ 40,000) of eight gamma-ray burst (GRB) afterglows to obtain the incidence (dN/dz) of weak intervening Mg II systems at a mean redshift of langzrang = 1.5. We show that dN/dz of systems having …

## An Imaging and Spectroscopic Study of Four Strong Mg II Absorbers Revealed by GRB 060418

We present results from an imaging and spectroscopic study of four strong Mg II absorbers of W(2796) gsim 1 ̊A revealed by the afterglow of GRB 060418 at z $_GRB$ = 1.491. These absorbers, at z = 0.603, 0.656, 1.107, and z $_GRB$, exhibit large ion …

## High-Redshift Starbursting Dwarf Galaxies Revealed by γ-Ray Burst Afterglows

We present a study of 15 long-duration γ-ray burst (GRB) host galaxies at z > 2. The GRBs are selected with available early-time afterglow spectra in order to compare interstellar medium (ISM) absorption-line properties with stellar properties of …