Related papers: Can internal shocks produce the variability in GRB…

Extreme sources in the Transient Universe show evidence of relativistic outflows from intermittent inner engines, such as cosmological gamma-ray bursts. They probably derive from rotating back holes interacting with surrounding matter. We…

Long gamma-ray bursts (GRBs) are commonly accepted to originate in the explosion of particularly massive stars, which gives rise to a highly relativistic jet. Internal inhomogeneities in the expanding flow give rise to internal shock waves…

We investigate the dynamics and radiation from a relativistic blast-wave which decelerates as it sweeps up ambient matter. The bulk kinetic energy of the blast-wave shell is converted into internal energy by the process of accreting…

Although the time profiles of gamma ray bursts (GRBs) show extremely diverse behavior, their average statistical properties such as the average peak-aligned profile and the auto-correlation function show simple stretched-exponential…

Many cosmological models of GRBs envision the energy source to be a cataclysmic stellar event leading to a relativistically expanding fireball. Particles are thought to be accelerated at shocks and produce nonthermal radiation. The highly…

We perform relativistic hydrodynamic simulations of internal shocks formed in microquasar jets by continuous variation of the bulk Lorentz factor, in order to investigate the internal shock model. We consider one-, two-, and flicker noise…

In this paper we study synchrotron and synchrotron self Compton (SSC) emission from internal shocks (IS) during the prompt and X-ray flare phases of Gamma-Ray Bursts (GRBs). The aim is to test the IS model for the flare emission and for…

Air shower experiments have detected cosmic ray events of energies upto 300 EeV. Most likely these cosmic rays have originated from compact objects. Their exact sources are yet to be identified. It has been suggested before that gamma ray…

We study afterglow flares of gamma-ray bursts (GRBs) in the framework of the late internal shock (LIS) model based on a careful description for the dynamics of a pair of shocks generated by a collision between two homogeneous shells,.…

Common models of blazars and gamma-ray bursts assume that the plasma underlying the ob- served phenomenology is magnetized to some extent. Within this context, radiative signatures of dissipation of kinetic and conversion of magnetic energy…

In the neutron-rich internal shocks model for Gamma-ray Burts (GRBs), the Lorentz factors (LFs) of ions shells are variable, so are the LFs of accompanying neutron shells. For slow neutron shells with a typical LF tens, the typical…

We propose that the internal energy of the GRB blast waves, thought to be stored in the form of relativistic protons co-moving with the blast wave, is converted explosively (i.e. on light crossing time scales) into relativistic electrons of…

Variability on time scales \delta t < t is observed in many gamma-ray burst afterglows. It is well known that there should be no such variability if the afterglow is emitted by external shock, which is produced by the interaction of…

Global linear stability analysis of a self-similar solution describing the interaction of a relativistic shell with an ambient medium is performed. The solution is shown to be unstable to convective Rayleigh-Taylor modes having angular…

We present the first general relativistic hydrodynamic models of the launch and evolution of relativistic jets and winds, driven by thermal energy deposition, possibly due to neutrino-antineutrino annihilation, in the close vicinity of…

We consider a speculative model for gamma-ray bursts (GRB), which predicts that the total kinetic energy in the ejected matter is less than the total energy in the gamma rays. There is also secondary energy in X-rays, which are emitted…

We study the hydrodynamical effects of two colliding shells, adopted to model internal shocks in various relativistic outflows such as gamma-ray bursts and blazars. We find that the density profiles are significantly affected by the…

Using the conservation of energy and momentum during collisions of any two shells, we consider the efficiency of gamma-ray bursts by assuming that the ejecta from the central engine are equally massive and have the same Lorentz factors. We…

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…

The relative-space-time-transformation (RSTT) paradigm and the interpretation of the burst-structure (IBS) paradigm are applied to probe the origin of the time variability of GRBs. Again GRB 991216 is used as a prototypical case, thanks to…