相关论文: Relativistic Jet Dynamics and Calorimetry of Gamma…

We present analytical modelling of conical relativistic jets, in order to evaluate the role of the jet opening angle on certain key parameters that are inferred from VLBI radio observations of blazar nuclear jets. The key parameters…

The major multi-epoch VLBA programs are described and discussed in terms of relativistic beaming models. Broadly speaking the observed kinematics are consistent with models having a parent population which is only mildly relativistic but…

We report the results of a 15 GHz (2 cm) multi-epoch VLBA program, begun in 1994 to study the outflow in radio jets ejected from quasars and active galaxies. The observed flow of 208 distinct features measured in 110 quasars, active…

High-resolution Very-Long-Baseline Interferometry observations of NGC 1052 show a two sided jet with several regions of enhanced emission and a clear emission gap between the two jets.This gap shrinks with increasing frequency and vanishes…

We present time-dependent axisymmetric magnetohydrodynamic simulations of the interaction of a relativistic magnetized wind produced by a proto-magnetar with a surrounding stellar envelope, in the first $\sim 10$ seconds after core…

We consider radiation of relativistic electrons accelerated within the jet extended boundary layer. Due to velocity shear across the boundary the observed jet/counterjet brightness ratio is diminished as compared to the one derived for the…

Whether gamma-ray bursts are highly beamed or not is a very difficult but important problem that we are confronted with. Some theorists suggest that beaming effect usually leads to a sharp break in the afterglow light curve during the…

The role of relativistic jets in unbinding the stellar envelope during a supernova (SN) associated with a gamma-ray burst (GRB) is unclear. To study that, we explore observational signatures of stellar explosions that are driven by jets. We…

For an expanding spherical relativistic shock, we derive relations between the parameters of downstream emitting zone and the quantities measured by a distant observer. These relations are formulated in terms of dimensionless effective…

Recent observational and theoretical studies have raised the possibility that the collimated outflows in gamma-ray burst (GRB) sources have two distinct components: a narrow (opening half-angle $\theta_{\rm n}$), highly relativistic…

We present simulations of relativistic jets propagating in a nonuniform medium. Specifically, we study the bending of jets propagating obliquely to the vector of the density-gradient. Our results are applied to the NGC 4258, where such a…

Context. The concomitant observation of gravitational wave and electromagnetic signals from a binary neutron star (BNS) merger in 2017 confirmed that these events can produce relativistic jets responsible for short Gamma-Ray Bursts (sGRBs).…

Following a suggestion that a directed relativistic explosion may have a universal intermediate asymptotic, we derive a self-similar solution for an ultra-relativistic jetted blast wave. The solution involves three distinct regions: an…

Particle acceleration is expected to be different between relativistic and non-relativistic collisionless shocks. We show that electromagnetic counterparts to gravitational waves (GWs), gamma-ray burst (GRB) afterglows, are ideal targets…

Achromatic breaks in afterglow light curves of gamma-ray bursts (GRBs) arise naturally if the product of the jet's Lorentz factor \gamma and opening angle \Theta_j satisfies (\gamma \Theta_j) >> 1 at the onset of the afterglow phase, i.e.,…

Geometry of relativistic jets in active galaxies provides important information about mechanisms of launching, collimation and acceleration of plasma flow. We propose a new method to probe a boundary shape of a jet on parsec scales -- in…

We numerically model the interaction between an expanding fireball and a stationary external medium whose density is either homogeneous or varies with distance as a power-law. The evolution is followed until most of the fireball kinetic…

Synchrotron and inverse Compton emission successfully explain the observed spectra of gamma-ray burst (GRB) afterglows. It is thought that most GRBs are products of extremely relativistic outflows and the afterglow marks the interaction of…

Relativistic outflows in the form of jets are common in many astrophysical objects. By their very nature, jets have angle dependent velocity profiles, Gamma = Gamma(r, theta, phi), where Gamma is the outflow Lorentz factor. In this work we…

This paper describes a multidimensional hydrodynamic code which can be used for the studies of relativistic astrophysical flows. The code solves the special relativistic hydrodynamic equations as a hyperbolic system of conservation laws…