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Title: EFFECTS OF NEUTRAL PARTICLES ON MODIFIED SHOCKS AT SUPERNOVA REMNANTS

Journal Article · · Astrophysical Journal Letters
 [1];  [2]
  1. Theory Center, Institute of Particle and Nuclear Studies, KEK (High Energy Accelerator Research Organization), 1-1 Oho, Tsukuba 305-0801 (Japan)
  2. Department of Earth and Space Science, Graduate School of Science, Osaka University, 1-1 Machikaneyama-cho, Toyonaka, Osaka 560-0043 (Japan)

H{alpha} emission from supernova remnants (SNRs) implies the existence of neutral hydrogens in the ambient medium. In the precursor of an SNR shock modified by cosmic rays (CRs), upstream plasmas are pushed by the CR pressure, but neutral particles are not, so that the relative velocity appears and some neutral particles become pickup ions by the charge exchange process in the precursor. We investigate how the pickup ions generated in the precursor affect the shock structure and the particle acceleration. If the CR pressure is larger than 20% of the shock ram pressure, the compression of the subshock becomes smaller than that without pickup ions because of the pressure of the pickup ions. Moreover, even if the shock is modified by CRs, the total compression ratio can be smaller than 4. In addition, the pickup ions play an important role for the injection into the particle acceleration. If the shock is a quasi-perpendicular shock and if the multiply reflected ion acceleration occurs, the CR spectrum can be harder than that of the test particle diffusive shock acceleration below GeV.

OSTI ID:
21452804
Journal Information:
Astrophysical Journal Letters, Vol. 721, Issue 1; Other Information: DOI: 10.1088/2041-8205/721/1/L43; ISSN 2041-8205
Country of Publication:
United States
Language:
English