Related papers: Gamma-ray bursts from alternating-current jets
Quasars with flat radio spectra and one-sided, arc-second scale, ~100 mJy GHz radio jets are found to have similar scale X-ray jets in about 60% of such objects, even in short 5 to 10 ks Chandra observations. Jets emit in the GHz band via…
We consider the transverse structure and stability properties of relativistic jets formed in the course of the collapse of a massive progenitor. Our numerical simulations show the presence of a strong shear in the bulk velocity of such…
A weakly magnetized ($\sim 10^7$G) neutron star, slowly spun up by accretion in an X-ray binary, crosses the instability boundary for r-mode instability at P=1--2 msec. The amplitude of the oscillation, which initially increases only at the…
In inhomogeneous optically thick synchrotron sources a substantial part of the electron population at low energies can be hidden by self-absorption and overpowered by high energy electrons in optically thin emission. These invisible…
Gamma-ray flares from Active Galactic Nuclei (AGN) show substantial variability on ultrafast timescales (i.e. shorter than the light crossing time of the AGN's supermassive black hole). We propose that ultrafast variability is a byproduct…
The high polarization observed in the prompt phase of some gamma-ray bursts (GRBs) arouses extensive studies on the emission mechanism. In this paper, we investigate the polarization properties of the synchrotron-self-Compton (SSC) process…
The nature of the jets and the role of magnetic fields in gamma-ray bursts (GRB) remains unclear. In a baryon-dominated jet only weak, tangled fields generated in situ through shocks would be present. In an alternative model, jets are…
It is proposed that gamma-ray bursts are created in the mergers of double neutron star binaries and black hole neutron star binaries at cosmological distances. Bursts with complex profiles and relatively long durations are the result of…
The recently discovered gamma-ray flares from the Crab nebula are generally attributed to the magnetic energy release in a highly magnetized region within the nebula. I argue that such a region naturally arises in the polar region of the…
The polarization of X-ray emission is a unique tool used to investigate the magnetic field structure around astrophysical objects. In this paper, we study the linear polarization of X-ray emissions from gamma-ray binary systems based on…
A phenomenological model is presented to explain the light curves of gamma-ray bursts. Gamma-rays are produced in a narrow beam which sweeps through space due to the precession of a slaved accretion disc. The light curve expected from such…
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 show that the collapsar model of gamma-ray bursts results in a series of successive shocks and rarefaction waves propagating in the "cork" of stellar material being pushed ahead of the jet, as it emerges from the massive stellar…
Sari and Piran have demonstrated that the time structure of gamma-ray bursts must reflect the time structure of their energy release. A model which satisfies this condition uses the electrodynamic emission of energy by the magnetized…
Gamma-ray bursts (GRBs) are bright extragalactic flashes of gamma-ray radiation and briefly the most energetic explosions in the Universe. Their catastrophic origin (the merger of compact objects or the collapse of massive stars) drives the…
Supercriticality of the same kind as that in a nuclear pile can take place in high-energy astrophysical objects producing a number of impressive effects. For example, it could cause an explosive release of the energy of a cloud of…
Despite that gamma-ray bursts is a phenomenon quite different from accreting compact objects, it could be that their hard X-ray emission is associated with a very similar mechanism of energy dissipation. In both cases, we could deal with…
Cosmological GRBs are discussed with an emphasis on their plausible connection with black holes. GRBs can be triggered by collapse of stellar-mass objects that leads to formation of a black hole and a transient debris disk with a huge…
Gamma-ray bursts (GRBs) have been widely argued to originate from binary compact object mergers or core collapses of massive stars. Jets from these systems may have two components, an inner, narrow sub-jet and an outer, wider sub-jet. Such…
We propose that repeated photoexcitation/ionization of high Z atoms of highly relativistic flows by star light in dense stellar regions followed by emission of decay/recombination photons, which are beamed and boosted to gamma ray energies…