PhD Thesis: Ion
Heating in Collisionless Shocks in Supernovae and The Heliosphere Download a full copy in PDF here. Abstract Collisionless shocks play
a role in many astrophysical phenomena, from coronal mass ejections (CMEs) in
the heliosphere to supernova remnants. Their role in heating and accelerating
particles is well accepted yet the exact mechanism for ion heating is not
well understood. Two systems, CMEs and supernova remnants, were examined to
determine the heating of heavy ions as they pass through collisionless shocks
thus providing a seed population for cosmic ray acceleration processes. Three
parameters are examined, the plasma beta, the Mach number of the shock and
the magnetic angle of the shock. CMEs heat heavy ions preferentially. This is
in contrast to the supernova data that show less than mass proportional heating.
In addition to these studies, heating in astrophysical systems involves neutral
atoms. A Monte Carlo model simulated neutral particles as they pass through
the shock. Neutrals can create a precursor to the shock additionally heating
the plasma. This work uses in situ data from the heliosphere to study astronomical
systems because of common shock properties is a unique way to study magnetic
components of shocks remotely. . |