Speaker
Yutaka Ohira
(Aoyama Gakuin University)
Description
The interstellar medium and ejecta of supernova are not always completely ionized. Such partially ionized plasmas are though to be unsuitable for cosmic ray acceleration. In order to study shock structures of collisionless shocks in partially ionized plasmas, we perform two-dimensional hybrid simulations. We find that large density fluctuations and large magnetic fields fluctuations are generated both in the upstream and downstream regions for high Alfven Mach number shocks. For the shock velocity Vs = 1333 km/s = 57 Va, the strong turbulence is generated in the downstream region by the upstream density fluctuations and the downstream magnetic field is amplified over 30 times the initial upstream magnetic fields. In addition, we find that the velocity distribution of downstream hydrogen atoms has three components for Vs = 1333 km/s. Observed shock structures suggest that diffusive shock acceleration can operate at perpendicular shocks propagating into partially ionized plasmas in real three-dimensional systems. If possible, we will present results of three-dimensional simulations.
| Registration number following "ICRC2015-I/" | 708 |
|---|---|
| Collaboration | -- not specified -- |
Primary author
Yutaka Ohira
(Aoyama Gakuin University)
