相关论文: Sub-photospheric shocks in relativistic explosions
We have estimated fluxes of neutrinos and gamma-rays that are generated from decays of charged and neutral pions from a pulsar surrounded by supernova ejecta in our galaxy, including an effect that has not been taken into consideration,…
Recent observations of supernovae, supernova remnants, and radio pulsars suggest that there are correlations between pulsar kicks and spins, infrared and gamma-ray line profiles, supernova polarizations, and ejecta debris fields. A…
Diffusive shock acceleration (DSA) at relativistic shocks is expected to be an important acceleration mechanism in a variety of astrophysical objects including extragalactic jets in active galactic nuclei and gamma ray bursts. These sources…
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 identify a novel physical mechanism that may be responsible for energy release in $\gamma$-ray bursts. Radial perturbations in the neutron core, induced by its collision with collapsing outer layers during the early stages of supernova…
Internal (IS) or external (ES) shocks in relativistic expanding shells are currently the best known mechanism for producing GRBs. We calculate the hydrodynamic conditions and the cooling processes in internal shocks, that occur when one…
We suggest that neutron star mergers eject an ultra-relativistic envelope of mass $m\sim 10^{-7}M_\odot$, which helps explain the gamma-ray burst from GW170817. One ejection mechanism is the ablation of the neutron star surface by the burst…
The 'event' that triggers a gamma ray burst cannot last for more than a few seconds. This is, however, long compared with the dynamical timescale of a compact stellar-mass object ($\sim 10^{-3}$ seconds). Energy is assumed to be released as…
Radiation from many astrophysical sources, e.g. gamma-ray bursts and active galactic nuclei, is believed to arise from relativistically shocked collisionless plasmas. Such sources often exhibit highly transient spectra evolving rapidly,…
Bow shocks around cataclysmic variables (CVs) have traditionally been identified with a single bright optical arc. This feature has been interpreted as the bow shock formed by the interaction between a sustained outflow and the interstellar…
Collisionless shocks are ubiquitous in the Universe and are held responsible for the production of non-thermal particles and high-energy radiation. In the absence of particle collisions in the system, theoretical works show that the…
Diffusive shock acceleration is invoked to explain non-thermal particle acceleration in Supernova Remnants, Active Galactic Nuclei (AGN) Jets, Gamma ray Bursts (GRBs) and various large scale cosmic structures. The importance of achieving…
Nonspherical mass motions are a generic feature of core-collapse supernovae, and hydrodynamic instabilities play a crucial role for the explosion mechanism. First successful neutrino-driven explosions could be obtained with self-consistent,…
In almost any scenario for 'cosmological' gamma-ray bursts (and in many models where they originate in our own Galaxy), the initial energy density is so large that the resulting relativistic plasma expands with $v\sim c$ producing a blast…
We have investigated particle acceleration and emission from shocks and shear flows associated with an unmagnetized relativistic jet plasma propagating into an unmagnetized ambient plasma. Strong electro-magnetic fields are generated in the…
Wave-driven outflows and non-disruptive explosions have been implicated in pre-supernova outbursts, supernova impostors, LBV eruptions, and some narrow-line and superluminous supernovae. To model these events, we investigate the dynamics of…
Shocks waves are a ubiquitous feature of many astrophysical plasma systems, and an important process for energy dissipation and transfer. The physics of these shock waves are frequently treated/modeled as a collisional, fluid MHD…
Waves launched from the neutron star surface or inner magnetosphere propagate through the magnetosphere as small perturbations, but can grow relative to the background magnetic field and steepen into ``monster shocks'' -- ultra-relativistic…
The discovery of strong gamma-ray and hard X-ray emission and the results from various multifrequency campaigns have disclosed new aspects of the blazar phenomenology, leading to a much more robust understanding of the mechanisms underlying…
The outflows from gamma ray bursts, active galactic nuclei and relativistic jets in general interact with the surrounding media through collisionless shocks. With three dimensional relativistic particle-in-cell simulations we investigate…