Related papers: Naked forward shock seen in the TeV afterglow data…

Gamma-ray bursts (GRBs) are believed to launch relativistic jets, which generate prompt emission by internal processes, and produce long-lasting afterglows by driving external shocks into surrounding medium. However, how the jet powers the…

Recent LHAASO observations of the prompt emission phase of the brightest-of-all-time GRB 221009A imposes a stringent limit on the flux ratio between the TeV and MeV emissions, $F_{\rm TeV}/F_{\rm MeV}\le 2\times10^{-5}$, during the period…

The TeV observations of GRB~221009A provided us with a unique opportunity to analyze the contemporaneous phase in which both prompt and afterglow emissions are seen simultaneously. To describe this initial phase of Gamma-Ray Burst…

Recently, LHAASO reported the detection of brightest-of-all-time GRB 221009A, revealing the early onset of a TeV afterglow. However, there is no evidence of afterglow emission at such early time at other wavelengths. Here we report the…

Recent detections of very high energy (VHE; GeV-TeV) photons from gamma-ray burst (GRB) afterglows, most notably the extreme event GRB 221009A, require refined models that include realistic jet structures and complex circumburst…

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…

The early afterglow of a Gamma-ray burst (GRB) can provide critical information on the jet and progenitor of the GRB. The extreme brightness of GRB 221009A allows us to probe its early afterglow in unprecedented detail. In this letter, we…

Gamma-Ray Burst GRB 241030A (z = 1.411) exhibited a bright afterglow (similar to GRB 221009A), detected across gamma-ray, X-ray, UV, and optical bands, providing a probe of GRB afterglow physics. We compiled multi-wavelength observations…

We present a new model for the TeV afterglow of GRB 221009A. The rapid increase of the TeV flux in the very early phase is reproduced by the magnetic acceleration. We consider the change in the radial structure of the circumstellar medium…

GRB afterglow jets have been notoriously difficult to resolve numerically using 2D hydrodynamical simulations due to high outflow Lorentz factors. By performing simulations in a boosted frame, it is possible to calculate light curves from…

Some gamma-ray bursts (GRBs) have an afterglow in the tera-electronvolt (TeV) band, but the early onset of this afterglow has not been observed. We report observations with the Large High Altitude Air Shower Observatory of the bright GRB…

Recently, GRB 221009A, known as the brightest of all time (BOAT), has been observed across an astounding range of $\sim 18$ orders of magnitude in energy, spanning from radio to VHE bands. Notably, the Large High Altitude Air Shower…

The afterglow of GRB$\,$170817A/GW$\,$170817 was very unusual, slowly rising as $F_\nu\propto{}t_{\rm{}obs}^{0.8}\nu^{-0.6}$, peaking at $t_{\rm{obs,pk}}\sim\,150\;$days, and sharply decaying as $\sim{}t_{\rm{}obs}^{-2.2}$. VLBI…

Observations of long duration gamma-ray bursts (GRBs) with TeV emission during their afterglow have been on the rise. Recently, GRB 221009A, the most energetic GRB ever observed, was detected by the {LHAASO} experiment in the energy band…

The 2-m robotic Liverpool Telescope (LT) reacted promptly to the high-redshift (z=4.048) gamma-ray burst GRB 060206. The afterglow was identified automatically and multicolor r'i'z' imaging was triggered without human intervention.…

Direct multi-dimensional numerical simulation is the most reliable approach for calculating the fluid dynamics and observational signatures of relativistic jets in gamma-ray bursts (GRBs). We present a two-dimensional relativistic…

GRB~221009A has been the brightest gamma-ray burst (GRB) observed to date, and its afterglow has been characterised with unprecedented detail at TeV energies by LHAASO. Quite puzzlingly, it is also the most energetic GRB known. Among the…

The optical light curve of the energetic gamma-ray burst GRB 991216 is consistent with jet-like behavior in which a power-law decay steepens from t**(-1.22 +/- 0.04) at early times to t**(-1.53 +/- 0.05) in a gradual transition at around 2…

We report our discovery and early time optical, near-infrared, and radio wavelength follow-up observations of the afterglow of the gamma-ray burst GRB 021211. Our optical observations, beginning 21 min after the burst trigger, demonstrate…

Recent detections of very-high-energy (VHE; $\gtrsim 100~{\rm GeV}$) emission from GRB afterglows, most notably the unprecedented brightness of GRB~221009A observed by LHAASO, reveal components beyond the standard electron synchrotron…