Related papers: Inverse-Compton drag on a Highly Magnetized GRB je…
The inner region of a luminous accretion disk is radiation pressure dominated. We estimate the surface temperature of a radiation pressure dominated accretion disk, \Theta=(c_s/r\Omega_K)^2<<(H/r)^2, which is significantly lower than that…
We present the results of hydrodynamical simulations of gamma-ray burst jets propagating through their stellar progenitor material and subsequently through the surrounding circumstellar medium. We consider both jets that are injected with…
Long duration gamma-ray bursts (GRBs) are thought to be produced by the core-collapse of a rapidly-rotating massive star. This event generates a highly relativistic jet and prompt gamma-ray and X-ray emission arises from internal shocks in…
Recent observations indicate that stripped-envelope core-collapse supernovae are often surrounded by dense circumstellar material (CSM). Motivated by this, we develop an analytic model to systematically study the dynamics of long gamma-ray…
We analyze how the spectrum of synchrotron and inverse Compton radiation from a narrow relativistic jet changes with the observation angle. It is shown that diversity of acceleration mechanisms (in particular, taking the converter mechanism…
We compare two possible scenarios for the producing of high level of polarization within the prompt emission of a GRB: synchrotron emission from a relativistic jet with a uniform (in space and time) magnetic field and synchrotron emission…
We describe a new numerical 3D relativistic hydrodynamical code, the results of validation tests, and a comparison with earlier, 2D studies. The 3D code has been used to study the deflection and precession of relativistic flows. We find…
The death of massive stars is accompanied by the formation of central and accreting compact objects and the subsequent launch of relativistic jets. However, not all jets successfully drill their way out of the stellar envelope. Unsuccessful…
We calculate the rate of in-fall of stellar matter on an accretion disk during the collapse of a rapidly rotating massive star, and estimate the luminosity of the relativistic jet that results from accretion on to the central black hole. We…
Powerful radio sources and quasars emit relativistic jets of plasma and magnetic fields that travel hundreds of kilo-parsecs, ultimately depositing energy into the intra- or inter-cluster medium. In the rest frame of the jet, the energy…
Synchrotron radiation mechanism, when electrons are accelerated in a relativistic shock, is known to have serious problems to explain the observed gamma-ray spectrum below the peak for most Gamma-Ray Bursts (GRBs); the synchrotron spectrum…
Radiative deceleration of relativistic jets in active galactic nuclei as the result of inverse Compton scattering of soft photons from accretion discs is discussed. The Klein-Nishina (KN) cross section is used in the calculation of the…
Gamma-ray bursts (GRBs) show a dramatic pulse structure that requires bulk relativistic motion, but whose physical origin has remained murky. We focus on a hot, magnetized jet that is emitted by a black hole and interacts with a confining…
We present numerical simulations of cold, axisymmetric, magnetically driven relativistic outflows. The outflows are initially sub-Alfv\'enic and Poynting flux-dominated, with total--to--rest-mass energy flux ratio up to $\mu \sim 620$. To…
The polarization of gamma ray emission scattered off the baryon rich material that collimates a GRB fireball and the coasting speed of the irradiated matter are calculated numerically for different geometries of the radiation source and the…
We calculate the synchrotron self-Compton emission from internal shocks occurring in relativistic winds as a source of gamma-ray bursts, with allowance for self-absorption. For plausible model parameters most pulses within a Gamma-Ray Burst…
We examine millisecond magnetars as central engines of Gamma Ray Bursts' (GRB) prompt emission. Using the proto-magnetar wind model of Metzger et al. 2011, we estimate the temporal evolution of the magnetization and power injection at the…
Relativistic jets associated with long/soft gamma-ray bursts are formed and initially propagate in the interior of the progenitor star. Because of the subsequent loss of their external pressure support after they cross the stellar surface,…
We model the interaction between the wind from a newly formed rapidly rotating magnetar and the surrounding progenitor. In the first few seconds after core collapse the magnetar inflates a bubble of plasma and magnetic fields behind the…
New high energy emission features have been recently discovered by the Cherenkov telescopes from active galaxies e.g., a few minutes variability time scale of TeV emission from Mrk 501 and PKS 2155-304, sub-TeV $\gamma$-ray emission from…