Related papers: GRB 000301C: a possible short/intermediate duratio…

We present a low-redshift (z=0.029) Damped Lyman-alpha (DLA) system in the spectrum of a background Quasi-Stellar Object (QSO). The DLA is associated with an interacting galaxy pair within a galaxy group. We detected weak Lyman-alpha…

We present a high-resolution, high signal-to-noise optical spectrum of the afterglow of GRB 051111 obtained with the HIRES spectrograph on the Keck I 10-m telescope. The spectrum exhibits three redshifted absorption systems with the…

We present optical spectra of the host galaxies of the short-duration gamma-ray burst GRB 070429B and the likely short-duration with extended emission GRB 070714B. In both cases, we find a single emission line that we identify as O II…

We study the properties of long gamma-ray burst (GRB) host galaxies using a statistical modelling framework derived to model damped Lyman-$\alpha$ absorbers (DLAs) in quasar spectra at high redshift. The distribution of NHI for GRB-DLAs is…

In order to constrain the broad-band spectral energy distribution of the afterglow of GRB 100621A, dedicated observations were performed in the optical/near-infrared with the 7-channel "Gamma-Ray Burst Optical and Near-infrared Detector"…

The optical afterglow of long-duration GRB 071003 is among the brightest yet to be detected from any GRB, with R ~ 12 mag in KAIT observations starting 42 s after the GRB trigger, including filtered detections during prompt emission.…

We present the discovery of a low-redshift damped Ly$\alpha$ (DLA) system in the spectrum of background starburst galaxy SDSS J111323.88+293039.3 ($z=0.17514$). The DLA is at an impact parameter of $\rm \rho=36~kpc$ from the star forming…

We present optical and X-ray observations of the afterglow and host galaxy of the short-hard GRB 060121. The faint R-band afterglow is seen to decline as t^(-0.66) while the X-ray falls as t^-1.18, indicating the presence of the cooling…

Based on near-infrared polarimetric observations we constrain the degree of linear polarization of the afterglow light of GRB 000301C to less than 30% 1.8 days after the burst.

GRB$\,$220831A is a gamma-ray burst (GRB) with a duration and spectral peak energy that places it at the interface between the distribution of long-soft and short-hard GRBs. In this paper, we present the multi-wavelength follow-up campaign…

Gamma-ray bursts (GRBs) display a bimodal duration distribution, with a separation between the short- and long-duration bursts at about 2 sec. The progenitors of long GRBs have been identified as massive stars based on their association…

The afterglow of the Gamma-Ray Burst (GRB) 000301C exhibited achromatic, short time-scale variability that is difficult to reconcile with the standard relativistic shock model. We interpret the observed light curves as a microlensing event…

We discuss our ongoing program of Target of Opportunity sub-millimeter observations of gamma-ray bursts (GRBs) using the Sub-millimetre Common-User Bolometer Array (SCUBA) on the James Clerk Maxwell Telescope (JCMT). Sub-millimeter…

Since the discovery of the first short-hard gamma-ray burst afterglows in 2005, the handful of observed events have been found to be embedded in nearby (z < 1), bright underlying galaxies. We present multiwavelength observations of the…

On 2006 May 5, a four second duration, low energy, ~10^49 erg, Gamma-Ray Burst (GRB) was observed, spatially associated with a z=0.0894 galaxy. Here, we report the discovery of the GRB optical afterglow and observations of its environment…

We report the discovery of the optical afterglow (OA) of the long-duration gamma-ray burst GRB 030429, and present a comprehensive optical/near-infrared dataset used to probe the matter at different distance scales, i.e. in the burst…

We present optical observations of the short/hard gamma-ray burst GRB 050709, the first such event with an identified optical counterpart. The object is coincident with a weak X-ray source and is located inside a galaxy at redshift z =…

We present a comprehensive multi-wavelength study of GRB 260310A / SN 2026fgk, a nearby ($z=0.153$), long-duration gamma-ray burst (GRB) with an exceptionally underluminous prompt $\gamma$-ray emission and a Comptonized spectrum. It is…

We present the photometric and spectroscopic analysis of the short-duration GRB 250221A ($T_{90}=1.80\pm0.32$ s), using a data set from the optical facilities COLIBR\'I, the Harlingten 50~cm Telescope, and the Very Large Telescope. We…

The CCD magnitudes in Johnson V and Cousins R and I photometric passbands are determined for GRB 000301C afterglow starting ~ 1.5 day after the gamma-ray burst. In fact we provide the earliest optical observations for this burst. Light…