intergalactic medium

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 …

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 …

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 …