Related papers: Multiwavelength afterglow light curves from magnet…
Gamma-ray bursts are most luminous explosions in the universe. Their ejecta are believed to move towards Earth with a relativistic speed. The interaction between this "relativistic jet" and a circum burst medium drives a pair of (forward…
GRB021211 was first detected by HETE II and its early afterglow has been observed. There is a break in its afterglow light curve at about 12 minutes after the bursts, before the break the optical flux decays with a power-law index of about…
According to the fireball model gamma-ray burst (GRB) afterglows are the result of a shock pushed into the surrounding medium by an extremely relativistic outflow from the GRB. By modeling the broadband spectrum, ranging from X-ray to radio…
The prompt emission of low-luminosity gamma-ray bursts (llGRBs) indicates that these events originate from a relativistic shock breakout. In this case we can estimate, based on the properties of the prompt emission, the energy distribution…
Gamma-ray bursts (GRBs) are the most luminous explosions in the universe, yet the nature and physical properties of their energy sources are far from understood. Very important clues, however, can be inferred by studying the afterglows of…
A nascent magnetar, accompanying a gamma-ray burst (GRB) explosion, releases enormous rotational energy via magnetic dipole radiation. The energy loss rate of the magnetar is determined by the strength of the magnetic field at the pole. We…
We present a comprehensive temporal and spectral analysis of the long-duration gamma-ray burst GRB 110801A, utilizing multi-band data from the Neil Gehrels Swift Observatory and ground-based telescopes. The $\gamma$-ray emission exhibits a…
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 calculate the creation of electron--positron pairs in Gamma-Ray Bursts (GRBs) resulting from the collision between scattered and outward moving gamma-ray photons. The number of pairs exceeds the number of ambient medium electrons…
We calculate the {\it afterglow} emission for Gamma-Ray Bursts (GRBs) going off in an extremely low density medium, referred to as {\it naked bursts}. Our results also apply to the case where the external medium density falls off sharply at…
Millisecond magnetars, one of the potential candidates for the central engine of Gamma-ray bursts (GRBs), can experience significant magnetic field enhancement shortly after their formation. In some cases, this evolution is further…
A long plateau phase and an amazing brightness have been observed in the Xray afterglow of GRB 060729. This peculiar light curve is likely due to long-term energy injection in external shock. Here we present a detailed numerical study on…
We present a detailed broadband afterglow study of GRB 220101A ($10^4\lesssim\Delta T\lesssim10^7$ s) combining multi-wavelength data from soft X-rays until 6 GHz. The afterglow light curves in both X-ray and optical show distinct…
We perform three-dimensional (3D) general-relativistic magnetohydrodynamic simulations to model the jet break-out from the ejecta expected to be produced in a binary neutron-star merger. The structure of the relativistic outflow from the 3D…
Gamma-ray burst are thought to be produced by highly relativistic outflows. Although upper and lower limits for the outflow initial Lorentz factor $\Gamma_0$ are available, observational efforts to derive a direct determination of…
The parameters of the GRB 000301c afterglow are determined within the usual framework of synchrotron emission from relativistic ejecta, through fits to the available radio-to-optical data. It is found that 1) the jet energy after the GRB…
We discuss the reference time t_0 of afterglow light curves in the context of the standard internal-external shock model. The decay index of early afterglow is very sensitive to the reference time one chooses. In order to understand the…
The short Gamma Ray Bursts (GRBs) are the aftermath of the merger of binary compact objects (neutron star -- neutron star or neutron star -- black hole systems). With the simultaneous detection of Gravitational Wave (GW) signal from GW…
Exceptionally bright gamma-ray burst (GRB) afterglows can reveal the angular structure of their jets. GRB jets appear to have a narrow core (of half-opening angle $\theta_c$), beyond which their kinetic energy drops as a power-law with…
In the fireball model, it is more physically realistic that gamma-ray burst (GRB) ejecta have a range of bulk Lorentz factors (assuming $M\propto \Gamma^{-s}$). The low Lorentz factor part of the ejecta will catch up with the high Lorentz…