Kinetic simulations of nonrelativistic perpendicular shocks of young supernova remnants. II. Influence of shock-surfing acceleration on downstream electron spectra. (arXiv:1909.05294v1 [astro-ph.HE])

Kinetic simulations of nonrelativistic perpendicular shocks of young supernova remnants. II. Influence of shock-surfing acceleration on downstream electron spectra. (arXiv:1909.05294v1 [astro-ph.HE])
<a href="http://arxiv.org/find/astro-ph/1/au:+Bohdan_A/0/1/0/all/0/1">Artem Bohdan</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Niemiec_J/0/1/0/all/0/1">Jacek Niemiec</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Pohl_M/0/1/0/all/0/1">Martin Pohl</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Matsumoto_Y/0/1/0/all/0/1">Yosuke Matsumoto</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Amano_T/0/1/0/all/0/1">Takanobu Amano</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Hoshino_M/0/1/0/all/0/1">Masahiro Hoshino</a>

We explore electron pre-acceleration at high Mach-number nonrelativistic
perpendicular shocks at, e.g., young supernova remnants, which are a
prerequisite of further acceleration to very high energies via diffusive shock
acceleration. Using fully kinetic particle-in-cell simulations of shocks and
electron dynamics in them, we investigate the influence of shock-surfing
acceleration at the shock foot on the nonthermal population of electrons
downstream of the shock. The shock-surfing acceleration is followed by further
energization at the shock ramp where the Weibel instability spawns a type of
second-order Fermi acceleration. The combination of these two processes leads
to the formation of a nonthermal electron population, but the importance of
shock-surfing acceleration becomes smaller for larger ion-to-electron mass
ratio in the simulation. We discuss the resulting electron spectra and the
relevance of our results to the physics of systems with real ion-to-electron
mass ratio and fully three-dimensional behavior.

We explore electron pre-acceleration at high Mach-number nonrelativistic
perpendicular shocks at, e.g., young supernova remnants, which are a
prerequisite of further acceleration to very high energies via diffusive shock
acceleration. Using fully kinetic particle-in-cell simulations of shocks and
electron dynamics in them, we investigate the influence of shock-surfing
acceleration at the shock foot on the nonthermal population of electrons
downstream of the shock. The shock-surfing acceleration is followed by further
energization at the shock ramp where the Weibel instability spawns a type of
second-order Fermi acceleration. The combination of these two processes leads
to the formation of a nonthermal electron population, but the importance of
shock-surfing acceleration becomes smaller for larger ion-to-electron mass
ratio in the simulation. We discuss the resulting electron spectra and the
relevance of our results to the physics of systems with real ion-to-electron
mass ratio and fully three-dimensional behavior.

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