skip to main content
OSTI.GOV title logo U.S. Department of Energy
Office of Scientific and Technical Information

Title: The Re-Acceleration of Galactic Electrons at the Heliospheric Termination Shock

Abstract

Observations by the Voyager spacecraft in the outer heliosphere presented several challenges for the paradigm of diffusive shock acceleration (DSA) at the solar wind termination shock (TS). In this study, the viability of DSA as a re-acceleration mechanism for galactic electrons is investigated using a comprehensive cosmic-ray modulation model. The results demonstrate that the efficiency of DSA depends strongly on the shape of the electron spectra incident at the TS, which in turn depends on the features of the local interstellar spectrum. Modulation processes such as drifts therefore also influence the re-acceleration process. It is found that re-accelerated electrons make appreciable contributions to intensities in the heliosphere and that increases caused by DSA at the TS are comparable to intensity enhancements observed by Voyager 1 ahead of the TS crossing. The modeling results are interpreted as support for DSA as a re-acceleration mechanism for galactic electrons at the TS.

Authors:
; ;  [1]
  1. Centre for Space Research, North-West University, 2520 Potchefstroom (South Africa)
Publication Date:
OSTI Identifier:
22663829
Resource Type:
Journal Article
Resource Relation:
Journal Name: Astrophysical Journal; Journal Volume: 836; Journal Issue: 1; Other Information: Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
79 ASTROPHYSICS, COSMOLOGY AND ASTRONOMY; ACCELERATION; COMPARATIVE EVALUATIONS; COSMIC RADIATION; EFFICIENCY; ELECTRON SPECTRA; ELECTRONS; HELIOSPHERE; MODULATION; SIMULATION; SOLAR WIND; SUN; VOYAGER SPACE PROBES

Citation Formats

Prinsloo, P. L., Potgieter, M. S., and Strauss, R. D., E-mail: marius.potgieter@nwu.ac.za. The Re-Acceleration of Galactic Electrons at the Heliospheric Termination Shock. United States: N. p., 2017. Web. doi:10.3847/1538-4357/836/1/100.
Prinsloo, P. L., Potgieter, M. S., & Strauss, R. D., E-mail: marius.potgieter@nwu.ac.za. The Re-Acceleration of Galactic Electrons at the Heliospheric Termination Shock. United States. doi:10.3847/1538-4357/836/1/100.
Prinsloo, P. L., Potgieter, M. S., and Strauss, R. D., E-mail: marius.potgieter@nwu.ac.za. Fri . "The Re-Acceleration of Galactic Electrons at the Heliospheric Termination Shock". United States. doi:10.3847/1538-4357/836/1/100.
@article{osti_22663829,
title = {The Re-Acceleration of Galactic Electrons at the Heliospheric Termination Shock},
author = {Prinsloo, P. L. and Potgieter, M. S. and Strauss, R. D., E-mail: marius.potgieter@nwu.ac.za},
abstractNote = {Observations by the Voyager spacecraft in the outer heliosphere presented several challenges for the paradigm of diffusive shock acceleration (DSA) at the solar wind termination shock (TS). In this study, the viability of DSA as a re-acceleration mechanism for galactic electrons is investigated using a comprehensive cosmic-ray modulation model. The results demonstrate that the efficiency of DSA depends strongly on the shape of the electron spectra incident at the TS, which in turn depends on the features of the local interstellar spectrum. Modulation processes such as drifts therefore also influence the re-acceleration process. It is found that re-accelerated electrons make appreciable contributions to intensities in the heliosphere and that increases caused by DSA at the TS are comparable to intensity enhancements observed by Voyager 1 ahead of the TS crossing. The modeling results are interpreted as support for DSA as a re-acceleration mechanism for galactic electrons at the TS.},
doi = {10.3847/1538-4357/836/1/100},
journal = {Astrophysical Journal},
number = 1,
volume = 836,
place = {United States},
year = {Fri Feb 10 00:00:00 EST 2017},
month = {Fri Feb 10 00:00:00 EST 2017}
}