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 …
The first gamma-ray burst (GRB) confirmed to be bright enough to be seen with the naked eye, GRB 080319B at redshift z = 0.937, allowed for exquisite follow-up observations across the electromagnetic spectrum. We present our detailed optical and …
Excited Si$^+$ and Fe$^+$ species are routinely observed in the host environment of gamma-ray burst (GRB) afterglows but are not commonly seen in other extragalactic locations. Their presence signals unusual properties in the gaseous environment of …
We report on the results of R-band observations of the error box of the γ-ray burst of 1997 August 28 made between 4 hr and 8 days after this burst occurred. No counterpart was found varying by more than 0.2 mag down to R=23.8. We discuss the …
We report on the results of R-band observations of the error box of the γ-ray burst of 1997 August 28 made between 4 hr and 8 days after this burst occurred. No counterpart was found varying by more than 0.2 mag down to R=23.8. We discuss the …