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dc.contributor.authorYu, F.
dc.contributor.authorKong, X.
dc.contributor.authorGuo, F.
dc.contributor.authorLiu, W.
dc.contributor.authorJiang, Z.
dc.contributor.authorChen, Y.
dc.contributor.authorGiacalone, J.
dc.date.accessioned2022-03-18T00:03:37Z
dc.date.available2022-03-18T00:03:37Z
dc.date.issued2022
dc.identifier.citationYu, F., Kong, X., Guo, F., Liu, W., Jiang, Z., Chen, Y., & Giacalone, J. (2022). Double-power-law Feature of Energetic Particles Accelerated at Coronal Shocks. Astrophysical Journal Letters.
dc.identifier.issn2041-8205
dc.identifier.doi10.3847/2041-8213/ac4cb3
dc.identifier.urihttp://hdl.handle.net/10150/663633
dc.description.abstractRecent observations have shown that in many large solar energetic particle (SEP) events the event-integrated differential spectra resemble double power laws. We perform numerical modeling of particle acceleration at coronal shocks propagating through a streamer-like magnetic field by solving the Parker transport equation, including protons and heavier ions. We find that for all ion species the energy spectra integrated over the simulation domain can be described by a double power law, and the break energy depends on the ion charge-to-mass ratio as E B ∼ (Q/A) α , with α varying from 0.16 to 1.2 by considering different turbulence spectral indices. We suggest that the double-power-law distribution may emerge as a result of the superposition of energetic particles from different source regions where the acceleration rates differ significantly due to particle diffusion. The diffusion and mixing of energetic particles could also provide an explanation for the increase of Fe/O at high energies as observed in some SEP events. Although further mixing processes may occur, our simulations indicate that either a power-law break or rollover can occur near the Sun and predict that the spectral forms vary significantly along the shock front, which may be examined by upcoming near-Sun SEP measurements from the Parker Solar Probe and Solar Orbiter. © 2022. The Author(s). Published by the American Astronomical Society..
dc.language.isoen
dc.publisherAmerican Astronomical Society
dc.rightsCopyright © 2022. The Author(s). Published by the American Astronomical Society. Original content from this work may be used under the terms of the Creative Commons Attribution 4.0 licence.
dc.rights.urihttps://creativecommons.org/licenses/by/4.0/
dc.titleDouble-power-law Feature of Energetic Particles Accelerated at Coronal Shocks
dc.typeArticle
dc.typetext
dc.contributor.departmentDepartment of Planetary Sciences, University of Arizona
dc.identifier.journalAstrophysical Journal Letters
dc.description.noteOpen access article
dc.description.collectioninformationThis 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 repository@u.library.arizona.edu.
dc.eprint.versionFinal published version
dc.source.journaltitleAstrophysical Journal Letters
refterms.dateFOA2022-03-18T00:03:37Z


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Copyright © 2022. The Author(s). Published by the American Astronomical Society. Original content from this work may be used under the terms of the Creative Commons Attribution 4.0 licence.
Except where otherwise noted, this item's license is described as Copyright © 2022. The Author(s). Published by the American Astronomical Society. Original content from this work may be used under the terms of the Creative Commons Attribution 4.0 licence.