Verification of Jupiter's X-ray emission mechanism for understanding particle acceleration in Jovian magnetosphere

2021 Fiscal Year Final Research Report

• Project/Area Number: 20K22375
• Research Category: Grant-in-Aid for Research Activity Start-up
• Allocation Type: Multi-year Fund
• Review Section: 0204:Astronomy, earth and planetary science, and related fields
• Research Institution: Tokyo Metropolitan University (2021); Institute of Physical and Chemical Research (2020)
• Principal Investigator: Numazawa Masaki 東京都立大学, 理学研究科, 特任助教 (10880437)
• Project Period (FY): 2020-09-11 – 2022-03-31
• Keywords: 木星 / Ｘ線天文学 / 惑星磁気圏 / 粒子加速

Outline of Final Research Achievements

In this study, we have verified the emission mechanism of diffuse hard X-ray emission from Jupiter using Jupiter X-ray data observed by Suzaku and a theoretical particle distribution model in the Jovian magnetosphere. Using our original analysis tools, we analyzed the observation data set in terms of both images and spectra, and developed a discussion on the spatial and energy distribution of high-energy electrons, which are related to the particle acceleration in the Jovian magnetosphere. The result provided the possibility of monitoring the Jovian magnetospheric particles in the future using such hard X-ray emissions from Jupiter as a new probe.

Free Research Field

Ｘ線天文学

Academic Significance and Societal Importance of the Research Achievements

本研究は木星系にＸ線観測という新たな手段を確立することを目指したものであり、惑星進化や系外惑星の理解に繋がる惑星科学の進展だけでなく、宇宙の様々なスケールで起こる粒子加速物理、プラズマ物理に寄与する成果へと発展しうる。電磁場を介した粒子加速の理解に、数十 MeV もの電子を加速する木星磁気圏が理想的な実験室としてもたらす知見は大きいと考える。本研究の成果は、木星磁気圏の高エネルギー粒子の分布を知る手段としてＸ線観測が有効であることを示唆するものである。