Vanthieghem A, Tsiolis V, Spitkovsky A, Todo Y, Sekiguchi K, Fiuza F
<a href="https://ror.org/02en5vm52">Sorbonne Université</a>, <a href="https://ror.org/029nkcm90">Observatoire de Paris</a>, Université PSL, CNRS, LERMA, F-75005 Paris, France.
Department of Astrophysical Sciences, <a href="https://ror.org/00hx57361">Princeton University</a>, Princeton, New Jersey 08544, USA.
Phys Rev Lett. 2024 Jun 28;132(26):265201. doi: 10.1103/PhysRevLett.132.265201.
The energy partition in high Mach number collisionless shock waves is central to a wide range of high-energy astrophysical environments. We present a new theoretical model for electron heating that accounts for the energy exchange between electrons and ions at the shock. The fundamental mechanism relies on the difference in inertia between electrons and ions, resulting in differential scattering of the particles off a decelerating magnetically dominated microturbulence across the shock transition. We show that the self-consistent interplay between the resulting ambipolar-type electric field and diffusive transport of electrons leads to efficient heating in the magnetic field produced by the Weibel instability in the high Mach number regime and is consistent with fully kinetic simulations.
