相关论文: Sub-photospheric shocks in relativistic explosions
Internal shocks between propagating plasma shells, originally ejected at different times with different velocities are believed to play a major role in dissipating the kinetic energy, thereby explaining the observed lightcurve and spectra…
Photons that decouple from a relativistic jet do so over a range of radii, which leads to a spreading in arrival times at the observer. Therefore, changes to the comoving photon distribution across the decoupling zone are encoded in the…
In this paper we reexamine the optical depth of ultrarelativistic spherically symmetric outflows and reevaluate the photospheric radius for each model during both the acceleration and coasting phases. It is shown that for both the wind and…
The temporal evolution of weak shocks in radiative media is theoretically investigated in this work. The structure of radiative shocks has traditionally been studied in a stationary framework. Their systematic classification is complex…
The transient emission produced behind internal shocks that are driven by overtaking collisions of a magnetized, relativistic outflow is considered. A self-consistent model capable of describing the structure and dynamics of the shocks and…
Gamma ray bursts are among the most energetic events in the known universe. A highly relativistic fireball is ejected. In most cases the burst itself is followed by an afterglow, emitted under deceleration as the fireball plunges through…
(Abridged): We study the collision of magnetized irregularities (shells) in relativistic outflows in order to explain the origin of the generic phenomenology observed in the non-thermal emission of both blazars and gamma-ray bursts. We…
We discuss the possibility that gamma-ray bursts result from internal shocks in an ultra-relativistic matter. Using a simple model we calculate the temporal structure and we estimate the efficiency of this process. In this model the…
lasma instabilities excited in collisionless shocks are responsible for particle acceleration. We have investigated the particle acceleration and shock structure associated with an unmagnetized relativistic electron-positron jet propagating…
Astrophysical sources of relativistic jets or outflows, such as gamma-ray bursts (GRBs), active galactic nuclei (AGN) or micro-quasars, often show strong time variability. Despite such impulsive behavior, most models of these sources assume…
Opacity effects in relativistic sources of high-energy gamma-rays, such as gamma-ray bursts (GRBs) or Blazars, can probe the Lorentz factor of the outflow and the distance of the emission site from the source, and thus help constrain the…
Shock waves in cold nuclear matter, e.g. those induced by a collision of two neutron stars, can generate a large number of gamma photons via parametric resonance. We study the resonant production of gamma rays inside a shocked neutron star…
In the Universe matter outside of stars and compact objects is mostly composed of collisionless plasma. The interaction of a supersonic plasma flow with an obstacle results in collisionless shocks that are often associated with intense…
We analyze the main features of radiation-mediated shocks at arbitrary shock velocities, both non-relativistic and relativistic. We describe two mechanisms, which may lead to formation of a sharp viscous subshock within otherwise smooth…
As a shock front interacts with turbulence, it develops corrugation which induces outgoing wave modes in the downstream plasma. For a fast shock wave, the incoming wave modes can either be fast magnetosonic waves originating from…
We study the dynamics of relativistic electromagnetic explosions as a possible mechanism for the production of Gamma-Ray Bursts. We propose that a rotating relativistic stellar-mass progenitor loses much of its spin energy in the form of an…
We explore the physics of relativistic radiation mediated shocks (RRMSs) in the regime where photon advection dominates over photon generation. For this purpose, a novel iterative method for deriving a self-consistent steady-state structure…
Shocks in relativistically hot plasmas are thought to exist in various high-energy astrophysical phenomena, but it is not clear how relativistic collisionless shocks are formed, whether particles are accelerated by the shock as in the case…
(Abbreviated) Particle-in-cell simulations of relativistic, weakly magnetized collisionless shocks show that particles can gain energy by repeatedly crossing the shock front. This requires scattering off self-generated small length-scale…
Thermal photons from the photosphere may be the primary source of the observed prompt emission of gamma-ray bursts (GRBs). In order to produce the observed non-thermal spectra, some kind of dissipation mechanism near the photosphere is…