Related papers: Collisional mechanism for GRB emission
Internal shocks provide a plausible heating mechanism in the jets of gamma-ray bursts (GRBs). Shocks occurring below the jet photosphere are mediated by radiation. It was previously found that radiation mediated shocks (RMSs) inside GRB…
Recent observations suggest that gamma ray bursts (GRBs) and their afterglows are produced by highly relativistic jets emitted in supernova explosions. We have proposed that the result of the event is not just a compact object plus the…
Short Gamma-Ray Bursts (SGRBs) are believed to arise from compact binary mergers (either neutron star-neutron star or black hole-neutron star). If so their jets must penetrate outflows that are ejected during the merger. As a jet crosses…
Gamma-ray bursts (GRBs) are the most electromagnetically luminous cosmic explosions. They are powered by collimated streams of plasma (jets) ejected by a newborn stellar-mass black hole or neutron star at relativistic velocities (near the…
A list of questions regarding Gamma Ray Bursts (GRBs) and Soft Gamma Repeaters (SGRs) remain unanswered within the Fireball-cone and Magnetar explosive scenarios. A persistent, thin (less than micron-sr solid angle) precessing and spinning…
After many years of speculation, recent observations have confirmed the association of gamma-ray bursts with core-collapse supernova explosions from massive stars. This association carries with it important consequences. The burst…
The extreme energetics of the gamma-ray burst (GRB) 990123 has revealed that some of GRBs emit quite a large amount of energy, and total energy release from GRBs seems to change from burst to burst by a factor of 10^{2-3} as E_{gamma, iso}…
If the threshold for $e^{-}e^{+}$ pair production depends on an angle between photon momenta, and if the $\gamma$-rays are collimated right in gamma-ray burst (GRB) source then another solution of the compactness problem is possible. The…
We introduce a new model of gamma ray burst (GRB) that explains its observed prompt signals, namely, its primary quasi-thermal spectrum and high energy tail. This mechanism can be applied to either assumption of GRB progenitor: coalescence…
The blast-wave model for gamma-ray bursts (GRBs) has been called into question by observations of spectra from GRBs that are harder than can be produced through optically thin synchrotron emission. If GRBs originate from the collapse of…
Even though the observed spectra for GRB prompt emission is well constrained, no single radiation mechanism can robustly explain its distinct non-thermal nature. Here we explore the radiation mechanism with the photospheric emission model…
It is proposed that the prompt emission observed in bursts that exhibit a thermal component originates from relativistic radiation mediated shocks that form below the photosphere of the GRB outflow. It is argue that such shocks are expected…
An elementary kinematic model for emission produced by relativistic spherical colliding shells is studied. The case of a uniform blast-wave shell with jet opening angle $\theta_j \gg 1/\Gamma$ is considered, where $\Gamma$ is the Lorentz…
A long duration photon beam can induce macroscopic coherent effects on a plasma by single photon electron scattering if the probability of the interaction approaches 1 in a volume of unit surface and length equal to the plasma typical…
The observational diversity of ``gamma-ray bursts'' (GRBs) has been increasing, and the natural inclination is a proliferation of models. We explore the possibility that at least part of this diversity is a consequence of a single basic…
We revisit the radiation mechanism of relativistic electrons in the stochastic magnetic field and apply it to the high-energy emissions of gamma-ray bursts (GRBs). We confirm that jitter radiation is a possible explanation for GRB prompt…
The optical and gamma-ray observations of GRB 080319B allow us to determine a fairly complete physical picture for this remarkable burst. The data indicate that the prompt optical and gamma-ray photons were produced at the same location but…
The MeV spectral peak of gamma-ray bursts (GRBs) is best explained as photospheric emission from a dissipative relativistic jet. The observed non-blackbody spectrum shows that sub-photospheric dissipation involves both thermal plasma…
The observations of jet breaks in the afterglows of short gamma-ray bursts (SGRBs) indicate that the jet has a small opening angle of < 10{\deg}. The collimation mechanism of the jet is a longstanding theoretical problem. We numerically…
It is generally supposed that a transition from the normal decay phase (decay slope $\sim -1$) to a steeper phase (decay slope $\sim -2$) could be suggested as a jet break. The jet opening angle $\theta_{\rm jet}$ is then calculated from…