Electron Bulk Acceleration and Thermalization at Earth's Quasiperpendicular Bow Shock

L.-J. Chen, S. Wang, L. B. Wilson, S. Schwartz, N. Bessho, T. Moore, D. Gershman, B. Giles, D. Malaspina, F. D. Wilder, R. E. Ergun, M. Hesse (+20 others)
2018 Physical Review Letters  
Electron heating at the Earth's quasi-perpendicular bow shock has been surmised to be due to the combined effects of a quasi-static electric potential and scattering through wave-particle interaction. Here we report the observation of electron distribution functions indicating a new electron heating process occurring at the leading edge of the shock front. Incident solar wind electrons are accelerated parallel to the magnetic field toward downstream, reaching an electron-ion relative drift
more » ... exceeding the electron thermal speed. The bulk acceleration is associated with an electric field pulse embedded in a whistler-mode wave. The high electron-ion relative drift is relaxed primarily through a nonlinear current-driven instability. The relaxed distributions contain a beam traveling
doi:10.1103/physrevlett.120.225101 pmid:29906189 fatcat:fbrsy3q55rdcfmc7zx666hvsim