Open AccessEvidence of magnetic flux ropes downstream of the heliospheric termination shock
Author(s) -
Lingling Zhao,
G. P. Zank,
L. Adhikari,
Qiang Hu,
J. A. le Roux
Publication year - 2020
Publication title -
journal of physics. conference series
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.21
H-Index - 85
eISSN - 1742-6596
pISSN - 1742-6588
DOI - 10.1088/1742-6596/1620/1/012027
Subject(s) - physics , magnetic reconnection , magnetohydrodynamics , magnetic flux , shock (circulatory) , magnetic helicity , flux (metallurgy) , helicity , particle acceleration , computational physics , plasma , acceleration , astrophysics , magnetic field , classical mechanics , nuclear physics , medicine , materials science , particle physics , quantum mechanics , metallurgy
Voyager 1 and 2 observed enhanced energetic particle fluxes downstream of the heliospheric termination shock. In this paper, we provide observational evidence of reconnection processes downstream of the shock by applying a wavelet analysis technique to three magnetohydrodynamics (MHD) invariants from the magnetic fleld and plasma fluctuations in the post-HTS region measured by Voyager 2. Our results suggest the existence of possible magnetic islands/flux ropes structures within ∼ 1 AU behind the HTS. The location and scales of these structures are characterized by wavelet spectrograms of the normalized reduced magnetic helicity, normalized cross helicity, and normalized residual energy. Transport theory suggests that these structures may contribute to the acceleration of energetic particles through magnetic reconnection processes. We use a kinetic transport theory to model the energetic proton flux in the region downstream of the HTS. Our results suggest that stochastic acceleration due to magnetic reconnection can explain the ACR proton flux enhancement at a short distance beyond the HTS.