相关论文: Electrostatic Potentials in Supernova Remnant Shoc…
The evidence for particle acceleration in supernova shells comes from electrons whose synchrotron emission is observed in radio and X-rays. Recent observations by the HESS instrument reveal that supernova remnants also emit TeV gamma-rays;…
High Mach number collisionless shocks are found in planetary systems and supernova remnants (SNRs). Electrons are heated at these shocks to the temperature well above the Rankine-Hugoniot prediction. However processes responsible for…
As supernova remnants (SNRs) age, they become efficient cosmic ray accelerators at their outer shell shocks. The current paradigm for shock acceleration theory favors turbulent field environs in the proximity of these shocks, turbulence…
Without amplification, magnetic fields in expanding ejecta of young supernova remnants (SNRs) will be orders of magnitude below those required to shock accelerate thermal electrons, or ions, to relativistic energies or to produce radio…
In strictly collisionless electrostatic shocks, the ion distribution function can develop discontinuities along phase-space separatrices, due to partial reflection of the ion population. In this paper, we depart from the strictly…
A significant fraction of the energy density of the interstellar medium is in the form of high-energy charged particles (cosmic rays). The origin of these particles remains uncertain. Although it is generally accepted that the only sources…
In the leptonic scenario for TeV emission from a few well-observed shell-type TeV supernova remnants (STTSNRs), very weak magnetic fields are inferred. If fast-mode waves are produced efficiently in the shock downstream, we show that they…
Nonrelativistic electrostatic unmagnetized shocks are frequently observed in laboratory plasmas and they are likely to exist in astrophysical plasmas. Their maximum speed, expressed in units of the ion acoustic speed far upstream of the…
Supernova remnants (SNRs) are believed to be the major contributors to Galactic cosmic rays. The detection of non-thermal emission from SNRs demonstrates the presence of energetic particles, but direct signatures of protons and other ions…
A number of supernova remnants (SNRs) show nonthermal X-rays assumed to be synchrotron emission from shock accelerated TeV electrons. The existence of these TeV electrons strongly suggests that the shocks in SNRs are sources of galactic…
We study the stochastic electron acceleration by fast mode waves in the turbulent downstream of weakly magnetized collisionless astrophysical shocks. The acceleration is most efficient in a dissipative layer, and the model characteristics…
If highly efficient, cosmic ray production can have a significant effect on the X-ray emission from SNRs as well as their dynamical evolution. Using hydrodynamical simulations including diffusive shock acceleration, we produce spectra for…
Context: Multiwavelength observations of supernova remnants can be explained within the framework of the diffusive shock acceleration theory, which allows effective conversion of the explosion energy into cosmic rays. Although the models of…
Supernova remnants (SNRs) are widely believed to be the principal source of galactic cosmic rays. Such energetic particles can produce gamma-rays and lower energy photons via interactions with the ambient plasma. In this paper, we present…
We have extended a simple model of nonlinear diffusive shock acceleration (Berezhko and Ellison 1999) to include the injection and acceleration of electrons and the production of photons from bremsstrahlung, synchrotron, inverse-Compton,…
Collisionless shock waves in supernova remnants and the solar wind heat electrons less effectively than they heat ions, as is predicted by kinetic simulations. However, the values of T$_e$/T$_p$ inferred from the H alpha profiles of…
%context {Recent observations of hard X-rays and very high energy gamma-rays from a number of young shell type supernova remnants indicate the importance of detailed quantitative studies of energy spectra of relativistic electrons formed…
We present results of semi-analytic calculations which show clear evidence for changes in the non-equilibrium ionization behind a supernova remnant forward shock undergoing efficient diffusive shock acceleration (DSA). The efficient…
Supernova remnants (SNRs) offer the means to study SN explosions, dynamics, and shocks at sub-parsec scales. X-ray observations probe the hot metals synthesized in the explosion and the TeV electrons accelerated by the shocks, and thus they…
We present results of 2D3V particle-in-cell simulations of non-relativistic plasma collisions with absent or parallel large-scale magnetic field for parameters applicable to the conditions at young supernova remnants. We study the collision…