相关论文: Infrared molecular hydrogen lines in GRB host gala…
(Abridged) We report on HST observations of the late-time afterglow and host galaxy of GRB021004 (z=2.33). Although this GRB is one of the best observed so far, there is substantial disagreement between different interpretations of data…
We aim to understand the nature of the absorbing neutral gas in the galaxies hosting high-redshift long-duration GRBs and to determine their physical conditions. We report the detection of a significant number of previously unidentified…
If Gamma-Ray-Bursts (GRBs) occur at high redshifts, then their bright afterglow emission can be used to probe the ionization and metal enrichment histories of the intervening intergalactic medium during the epoch of reionization. In…
The rapid dissemination of an arcmin-sized HETE-2 localization of the long-duration X-ray flash GRB 030528 led to a ground-based multi-observatory follow-up campaign. We report the discovery of the near-IR afterglow, and also describe the…
We present early time, high resolution spectroscopy of three GRB afterglows: GRB050730, 050922C and 060418. These data give us precious information on the kinematics, ionization and metallicity of the interstellar matter of GRB host…
We present K-band imaging observations of ten Gamma-Ray Burst (GRB) host galaxies. We compare their observed and absolute K magnitudes as well as their R-K colours with those of other distant sources detected in various optical,…
We reveal multiple components of an interacting galaxy system at $z\approx3.35$ through a detailed analysis of the exquisite high-resolution Keck/HIRES spectrum of the afterglow of a gamma-ray burst (GRB). Through Voigt-profile fitting of…
Aims: With this paper we want to investigate the highly variable afterglow light curve and environment of gamma-ray burst (GRB) 060526 at $z=3.221$. Methods: We present one of the largest photometric datasets ever obtained for a GRB…
We analyse the distribution of matter around the progenitor star of gamma-ray burst GRB 021004 as well as the properties of its host galaxy with high-resolution echelle as well as near-infrared spectroscopy. Observations were taken by the…
We detect the optical afterglow and host galaxy of GRB 070714B. Our observations of the afterglow show an initial plateau in the lightcurve for approximately the first 5 to 25 minutes, then steepening to a powerlaw decay with index alpha=…
The purported spiral host galaxy of GRB 020819B at z=0.41 has been seminal in establishing our view of the diversity of long-duration gamma-ray burst environments: optical spectroscopy of this host provided evidence that GRBs can form even…
If a gamma ray burst with strong UV emission occurs in a molecular cloud, there will be observable consequences resulting from excitation of the surrounding H2. The UV pulse from the GRB will pump H2 into vibrationally-excited levels which…
The extreme brightness of gamma-ray burst (GRB) afterglows and their simple spectral shape make them ideal beacons to study the interstellar medium of their host galaxies through absorption line spectroscopy. Using 69 low-resolution GRB…
Recent studies have revealed a dynamic interplay between the galaxy ecosystem and the circumgalactic medium (CGM). We investigate the CGM at high redshifts (z $\gtrsim$ 2) by using bright afterglows of gamma-ray bursts (GRB) as background…
Studies of the cosmic gamma-ray bursts (GRBs) and their host galaxies are now starting to provide interesting or even unique new insights in observational cosmology. Observed GRB host galaxies have a median magnitude R ~ 25 mag, and show a…
Aim: We present early optical spectroscopy of the afterglow of the gamma-ray burst GRB 060206 with the aim of determining the metallicity of the GRB absorber and the physical conditions in the circumburst medium. We also discuss how GRBs…
We present a study of the environment of the Swift long gamma-ray burst GRB 120327A at z ~2.8 through optical spectroscopy of its afterglow. We analyzed medium-resolution, multi-epoch spectroscopic observations (~7000 - 12000, corresponding…
We report our identification of the optical afterglow and host galaxy of the short-duration gamma-ray burst GRB 160821B. The spectroscopic redshift of the host is $z=0.162$, making it one of the lowest redshift sGRBs identified by Swift.…
Observations of gamma ray bursts (GRB) afterglows in different spectral bands provide a most valuable information about their nature, as well as about properties of surrounding medium. Powerful infrared afterglow was observed from the…
Gamma-ray bursts (GRBs) and their afterglows have been proposed as an excellent probe to study the evolution of cosmic star formation, the reionization of the intergalactic medium, and the metal enrichment history of the universe, since the…