2015/04/02 by Yuto Teraki, Hirotaka Ito, Shigehiro Nagataki
Physics and Astronomy · #Acceleration #Astrophysics and Cosmic Phenomena #Cosmology and Gravitation Theories #Electromagnetic radiation #Electron #Particle acceleration #Population #Pulsar #Pulsars and Gravitational Waves Research #Shock (circulatory) #Shock wave #Superluminal motion #astro-ph.HE
paper · pdf · doi:10.1088/0004-637x/805/2/138
Accepted for publication in ApJ (25 pages, 6 figures)
arxiv created 2015/04/02 · openalex publication_date 2015/05/28 · arxiv updated 2015/06/03 · openalex created_date 2016/06/24 · openalex updated_date 2026/08/05
We calculate the electron acceleration in random superluminal strong waves (SLSWs) and radiation from them using numerical methods in the context of the termination shocks of pulsar wind nebulae. We pursue the orbit of electrons by solving the equation of motion in the analytically expressed electromagnetic turbulences. These consist of a primary SLS and isotropically distributed secondary electromagnetic waves. Under the dominance of the secondary waves, all electrons gain nearly equal energy. On the other hand, when the primary wave is dominant, selective acceleration occurs. The phase of the primary wave for electrons moving nearly along the wavevector changes very slowly compared with the oscillation of the wave, which is "phase-locked," and such electrons are continuously accelerated. This acceleration by SLSWs may play a crucial role in pre-shock acceleration. In general, the radiation from the phase-locked population is different from the synchro-Compton radiation. However, when the amplitude of the secondary waves is not extremely weaker than that of the primary wave, the typical frequency can be estimated from synchro-Compton theory using the secondary waves. The primary wave does not contribute to the radiation because the SLSW accelerates electrons almost linearly. This radiation can be observed as a radio knot at the upstream of the termination shocks of the pulsar wind nebulae without counterparts in higher frequency ranges.