Jupiter's X-ray and EUV auroras monitored by Chandra, XMM-Newton, and Hisaki satellite
File(s)Kimura et al., 2016.pdf (2.12 MB)
Published version
Author(s)
Type
Journal Article
Abstract
Jupiter's X-ray auroral emission in the polar cap region results from particles which have undergone strong field-aligned acceleration into the ionosphere. The origin of precipitating ions and electrons and the time variability in the X-ray emission are essential to uncover the driving mechanism for the high-energy acceleration. The magnetospheric location of the source field line where the X-ray is generated is likely affected by the solar wind variability. However, these essential characteristics are still unknown because the long-term monitoring of the X-rays and contemporaneous solar wind variability has not been carried out. In April 2014, the first long-term multiwavelength monitoring of Jupiter's X-ray and EUV auroral emissions was made by the Chandra X-ray Observatory, XMM-Newton, and Hisaki satellite. We find that the X-ray count rates are positively correlated with the solar wind velocity and insignificantly with the dynamic pressure. Based on the magnetic field mapping model, a half of the X-ray auroral region was found to be open to the interplanetary space. The other half of the X-ray auroral source region is magnetically connected with the prenoon to postdusk sector in the outermost region of the magnetosphere, where the Kelvin-Helmholtz (KH) instability, magnetopause reconnection, and quasiperiodic particle injection potentially take place. We speculate that the high-energy auroral acceleration is associated with the KH instability and/or magnetopause reconnection. This association is expected to also occur in many other space plasma environments such as Saturn and other magnetized rotators.
Date Issued
2016-03-22
Date Acceptance
2016-01-29
Citation
Journal of Geophysical Research: Space Physics, 2016, 121 (3), pp.2308-2320
ISSN
2169-9402
Publisher
American Geophysical Union (AGU)
Start Page
2308
End Page
2320
Journal / Book Title
Journal of Geophysical Research: Space Physics
Volume
121
Issue
3
Copyright Statement
© 2016 American Geophysical Union. All Rights Reserved.
Publication Status
Published