AffiliationUniv Arizona, Lunar & Planetary Lab
Keywordsacceleration of particles
Sun: coronal mass ejections (CMEs)
MetadataShow full item record
PublisherIOP PUBLISHING LTD
CitationParticle Acceleration in Two Converging Shocks 2017, 842 (2):74 The Astrophysical Journal
JournalThe Astrophysical Journal
Rights© 2017. The American Astronomical Society. All rights reserved.
Collection InformationThis item from the UA Faculty Publications collection is made available by the University of Arizona with support from the University of Arizona Libraries. If you have questions, please contact us at firstname.lastname@example.org.
AbstractObservations by spacecraft such as ACE, STEREO, and others show that there are proton spectral "breaks" with energy E-br at 1-10 MeV in some large CME-driven shocks. Generally, a single shock with the diffusive acceleration mechanism would not predict the "broken" energy spectrum. The present paper focuses on two converging shocks to identify this energy spectral feature. In this case, the converging shocks comprise one forward CME-driven shock on 2006 December 13 and another backward Earth bow shock. We simulate the detailed particle acceleration processes in the region of the converging shocks using the Monte Carlo method. As a result, we not only obtain an extended energy spectrum with an energy "tail" up to a few 10 MeV higher than that in previous single shock model, but also we find an energy spectral "break" occurring on similar to 5.5 MeV. The predicted energy spectral shape is consistent with observations from multiple spacecraft. The spectral "break," then, in this case is caused by the interaction between the CME shock and Earth's bow shock, and otherwise would not be present if Earth were not in the path of the CME.
VersionFinal published version
SponsorsXinjiang Natural Science Foundation [2014211A069]; CAS Key Laboratory of Solar Activity, National Astronomical Observatories; Key Laboratory of Modern Astronomy and Astrophysics (Nanjing University), Ministry of Education; China Scholarship Council (CSC); XAO Director Foundation; NSFC [11673056, 11403087]; Supercomputer Center of University of Arizona