ISM: Molecules

The Discovery of Vibrationally Excited H2 in the Molecular Cloud Near GRB 080607

GRB 080607 has provided the first observational signatures of molecular absorption bands toward any galaxy hosting a gamma-ray burst (GRB). Despite the identification of dozens of features as belonging to various atomic and molecular (H2 and CO) …

The First Positive Detection of Molecular Gas in a GRB Host Galaxy

We report on strong H2 and CO absorption from gas within the host galaxy of gamma-ray burst (GRB) 080607. Analysis of our Keck/LRIS afterglow spectrum reveals a very large H I column density (N_H I = 10̂22.70 ± 0.15 cm-̂2) and strong metal-line …

Missing Molecular Hydrogen and the Physical Conditions of GRB Host Galaxies

We examine the abundance of molecular hydrogen (H2) in the spectra of gamma ray burst afterglows (GRBs). In nearby galaxies, H2 traces the cold neutral medium (CNM) and dense molecular star-forming interstellar gas. Although H2 is detected …