Related papers: "Dark" GRB 080325 in a Dusty Massive Galaxy at z ~…

We report on observations of the fading optical counterpart of the gamma-ray burst GRB 970228, made with the Hubble Space Telescope STIS CCD approximately six months after outburst and with the HST/NICMOS and Keck/NIRC approximately one…

We report the discovery of a radio transient VLA 232937.2-235553, coincident with the proposed X-ray afterglow for the gamma-ray burst GRB 981226. This GRB has the highest ratio of X-ray to gamma-ray fluence of all the GRBs detected by…

An important parameter for the distinction of X-ray flashes, X-ray rich bursts and Gamma-ray bursts in the rest frame is the distance to the explosion site. Here we report on the spectroscopic redshift determination of the host galaxy of…

We present and discuss optical diagnostics of the low redshift (z<0.2) galaxies that are known to have hosted supernovae associated with gamma-ray bursts (GRBs). The three galaxies are all actively starforming sub-luminous (L<L*) galaxies…

We present low-resolution VLT spectroscopy of the afterglow of the gamma-ray bursts (GRBs) 991216, 011211 and 021211. Our spectrum of GRB991216 is the only optical spectrum for this afterglow. It shows two probable absorption systems at…

We present late-time Hubble Space Telescope imaging of the fields of six Swift GRBs lying at 5.0<z<9.5. Our data includes very deep observations of the field of the most distant spectroscopically confirmed burst, GRB 090423, at z=8.2. Using…

We present early optical photometry and spectroscopy of the afterglow and host galaxy of the bright short-duration gamma-ray burst GRB 130603B discovered by the Swift satellite. Using the Gemini South telescope, our prompt optical spectra…

The chemical characterization of galaxies in the first billion years after the Big Bang is one of the central goals of current astrophysics. Optical/near-infrared spectroscopy of long gamma-ray bursts (GRBs) have been heralded as an…

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…

In this work, we present the results obtained from a multi-wavelength campaign, as well as from the public Swift/BAT, XRT, and UVOT data of GRB 060111B for which a bright optical emission was measured with good temporal resolution during…

We present an echelle spectrum of the Swift GRB 050730, obtained four hours after the burst using the MIKE spectrograph on the Magellan Clay Telescope when the afterglow was at R=17.7. The spectrum reveals a forest of absorption features…

We report the detection of the radio afterglow of a long gamma-ray burst (GRB) 111005A at 5-345 GHz, including the very long baseline interferometry observations with the positional error of 0.2 mas. The afterglow position is coincident…

At z=0.1055, the gamma-ray burst GRB 031203 is one of the two nearest GRBs known. Using observations from the Very Large Array (VLA) and Chandra X-ray Observatory, we derive sub-arcsecond localizations of the radio and X-ray afterglow of…

In a cosmological context dust has been always poorly understood. That is true also for the statistic of GRBs so that we started a program to understand its role both in relation to GRBs and in function of z. This paper presents a composite…

Dust in the host galaxies of gamma-ray bursts (GRBs) dims and reddens their afterglow spectra. Knowledge of the nature of this dust is crucial for correcting for extinction, providing clues to the nature of GRB progenitors, and probing the…

We report the discovery of the optical and radio afterglow of GRB 010921, the first gamma-ray burst afterglow to be found from a localization by the High Energy Transient Explorer (HETE) satellite. We present optical spectroscopy of the…

Long-duration gamma-ray bursts (GRBs) are indisputably related to star formation, and their vast luminosity in gamma rays pin-points regions of star formation independent of galaxy mass. As such, GRBs provide a unique tool for studying star…

At high redshift, the universe was so young that core-collapse supernovae (SNe) are suspected to be the dominant source of dust production. However, some observations indicate that the dust production by SNe is an inefficient process,…

The gamma-ray bursts hosts (GRBHs) are excellent targets to study the extinction properties of dust and its effects on the global emission of distant galaxies. The dust extinction curve is measured along the GRB afterglow line of sight and…

We present the results of deep imaging of the field of GRB 050904 with Suprime-Cam on the Subaru 8.2m telescope. We have obtained a narrow-band (130 A) image centered at 9200 A (NB921) and an i'-band image with total integration times of…