Quasi-adiabatic and stochastic heating and particle acceleration at quasi-perpendicular shocks

Stasiewicz, Krzysztof and Eliasson, Bengt (2020) Quasi-adiabatic and stochastic heating and particle acceleration at quasi-perpendicular shocks. Astrophysical Journal, 903 (1). 57. ISSN 1538-4357 (https://doi.org/10.3847/1538-4357/abb825)

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Abstract

Based on Magnetospheric Multiscale observations from the Earth’s bow shock, we have identified two plasma heating processes that operate at quasi-perpendicular shocks. Ions are subject to stochastic heating in a process controlled by the heating function c j = m jq j -1B -2 div(Ê) for particles with mass m j and charge q j in the electric and magnetic fields E and B. Test-particle simulations are employed to identify the parameter ranges for bulk heating and stochastic acceleration of particles in the tail of the distribution function. The simulation results are used to show that ion heating and acceleration in the studied bow shock crossings is accomplished by waves at frequencies (2–10)f cp (proton gyrofrequency) for the bulk heating, and f > 10f cp for the tail acceleration. When electrons are not in the stochastic heating regime, c e∣ < 1, they undergo a quasi-adiabatic heating process characterized by the isotropic temperature relation T B = (T 0 B 0)(B 0 B) 1 3. This is obtained when the energy gain from the conservation of the magnetic moment is redistributed to the parallel energy component through the scattering by waves. The results reported in this paper may be applicable also to particle heating and acceleration at astrophysical shocks.

  • Item type:Article
    ID code:73540
    Dates:
    Date
    Event
    2 November 2020
    Published
    10 September 2020
    Accepted
    2 August 2020
    Submitted
    Subjects:Science > Physics
    Department:Faculty of Science > Physics
    Depositing user: Pure Administrator
    Date deposited:11 Aug 2020 13:13
    Last modified:12 Apr 2024 04:43
    Related URLs:
    URI:https://strathprints.strath.ac.uk/id/eprint/73540
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