Jupiter's X-ray and EUV auroras monitored by Chandra, XXM-Newton, and Hisaki satellite

Badman, S. V.; Branduardi-Raymont, G.; Dunn, W. R.; Elsner, R. F.; Ezoe, Y.; Fujimoto, M.; Gladstone, G. R.; Hasegawa, H.; Kimura, T.; Kraft, R. P.; Masters, A.; Murakami, G.; Murray, S. S.; Roediger, E.; Tao, C.; Tsuchiya, F.; Vogt, M. F.; Yamazaki, A.; Yoshikawa, I.; Yoshioka, K.

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.

Citation

Badman, S. V., Branduardi-Raymont, G., Dunn, W. R., Elsner, R. F., Ezoe, Y., Fujimoto, M., Gladstone, G. R., Hasegawa, H., Kimura, T., Kraft, R. P., Masters, A., Murakami, G., Murray, S. S., Roediger, E., Tao, C., Tsuchiya, F., Vogt, M. F., Yamazaki, A., Yoshikawa, I., & Yoshioka, K. (2016). Jupiter's X-ray and EUV auroras monitored by Chandra, XXM-Newton, and Hisaki satellite. Journal of Geophysical Research: Space Physics, 121(3), 2308-2320. https://doi.org/10.1002/2015ja021893

• Journal Article Type: Article
• Acceptance Date: Jan 29, 2016
• Online Publication Date: Mar 22, 2016
• Publication Date: Mar 1, 2016
• Deposit Date: Sep 21, 2016
• Publicly Available Date: Sep 21, 2016
• Journal: Journal of geophysical research : space physics
• Print ISSN: 2169-9402
• Publisher: American Geophysical Union
• Peer Reviewed: Peer Reviewed
• Volume: 121
• Issue: 3
• Pages: 2308-2320
• DOI: https://doi.org/10.1002/2015ja021893
• Keywords: Jupiter, X-ray, Magnetosphere
• Public URL: https://hull-repository.worktribe.com/output/443251
• Publisher URL: http://onlinelibrary.wiley.com/doi/10.1002/2015JA021893/abstract;jsessionid=BE031B99A7BC7F5343A61F4B229D752D.f04t04
• Additional Information: This is a copy of an article published in: Journal of geophysical research : space physics, 2016, v.121 issue 3.
• Contract Date: Sep 21, 2016