Related papers: Theoretical Description Of GRB 160625B with Wind-t…
We present very early ground-based optical follow-up observations of GRB~140423A, which was discovered by \emph{Swift}/BAT and by {\it Fermi}/GBM. Its broadband afterglow was monitored by {\it Swift}/XRT and ground-based optical telescopes…
The collapse of a massive star is believed to be the most probable progenitor of a long GRB. Such a star is expected to modify its environment by stellar wind. The effect of such a circum-stellar wind medium is expected to be seen in the…
We present a detailed study of the prompt and afterglow emission from Swift GRB 061126 using BAT, XRT, UVOT data and multi-color optical imaging from ten ground-based telescopes. GRB 061126 was a long burst (T_90=191 s) with four…
Early multiwavelength observations offer crucial insights into the nature of the relativistic jets responsible for gamma-ray bursts and their interaction with the surrounding medium.We present data of GRB 240825A from 17 space- and…
We present Follow-Up Network for Gamma-Ray Bursts (FUN GRB) Collaboration observations of the optical afterglow of GRB 021211 made between 143 seconds and 102 days after the burst. Our unique data set includes the earliest filtered…
We present results of Swift optical, UV and X-ray observations of the afterglow of GRB 050801. The source is visible over the full optical, UV and X-ray energy range of the Swift UVOT and XRT instruments.Both optical and X-ray lightcurves…
We present the prompt BAT and afterglow XRT data of Swift-discovered GRB081109A up to ~ 5\times 10^5 sec after the trigger, and the early ground-based optical follow-ups. The temporal and spectral indices of the X-ray afterglow emission…
The Swift era has posed a challenge to the standard blast-wave model of Gamma Ray Burst (GRB) afterglows. The key observational features expected within the model are rarely observed, such as the achromatic steepening (`jet-break') of the…
The bright, short and hard GRB 090510 was detected by all instruments aboard Fermi and Swift satellites. The multiwavelength observations of this burst presented similar features with the Fermi-LAT-detected gamma-ray bursts. In the…
The detection of gravitational waves together with their electromagnetic counterpart, in the gamma-ray burst GRB 170817A, marked a new era of multi-messenger astronomy. Several theoretical models have been proposed to explain the atypical…
Context: Multiwavelength observations of gamma-ray burst prompt and afterglow emission are a key tool to disentangle the various possible emission processes and scenarios proposed to interpret the complex gamma-ray burst phenomenology.…
We present broad-band radio observations of the afterglow of GRB000301C, spanning from 1.4 to 350 GHz for the period of 3 to 83 days after the burst. This radio data, in addition to measurements at the optical bands, suggest that the…
GRB 160821B is a short duration gamma-ray burst (GRB) detected and localized by the Neil Gehrels Swift Observatory in the outskirts of a spiral galaxy at z=0.1613, at a projected physical offset of 16 kpc from the galaxy's center. We…
Swift triggered on a precursor to the main burst of GRB 061121 (z=1.314), allowing observations to be made from the optical to gamma-ray bands. Many other telescopes, including Konus-Wind, XMM-Newton, ROTSE and the Faulkes Telescope North,…
We present post-jet-break \textit{HST}, VLA and \textit{Chandra} observations of the afterglow of the long $\gamma$-ray bursts GRB 160625B (between 69 and 209 days) and GRB 160509A (between 35 and 80 days). We calculate the post-jet-break…
GRB 130925A is a peculiar event characterized by an extremely long gamma-ray duration ($\approx$7 ks), as well as dramatic flaring in the X-rays for $\approx$20 ks. After this period, its X-ray afterglow shows an atypical soft spectrum with…
Likely progenitors for the GRBs (gamma-ray bursts) are the mergers of compact objects or the explosions of massive stars. These two cases have distinctive environments for the GRB afterglow: the compact object explosions occur in the ISM…
We present and perform a detailed analysis of multi-wavelength observations of \thisgrb, an optical bright GRB with an observed reverse shock (RS) signature. Observations of this GRB were acquired with the BOOTES-4 robotic telescope, the…
Observations of very early multi-wavelength afterglows are critical to reveal the properties of the radiating fireball and its environment as well as the central engine of gamma-ray bursts (GRBs). We report our optical observations of GRB…
A significant fraction of the energy from the $\gamma$-ray burst (GRB) jets, after powering the keV-MeV emission, forms an ultra-relativistic shock propagating into the circumburst medium. The particles in the medium accelerate through the…