DATE2025.01.14 #Press Releases
Cosmic Radio Waves "Chirping" Discovered Traces of Accelerated Electrons in a Short Time
-Ultrafast Electron Acceleration in the Universe - A New Analytical Method-
Summary
Associate Professor Satoshi Kurita of Research Institute for Sustainable Humanosphere, Kyoto University, together with a research team led by Professor Yoshizumi Miyoshi of the Space and Earth Environment Research Institute, Nagoya University, Senior Researcher Shinji Saito of the National Institute of Information and Communications Technology (NICT), and Associate Professor Satoshi Kasahara of the School of Science, The University of Tokyo, have demonstrated that the naturally occurring radio waves called a “chorus” in space rapidly accelerate electrons for a short time, less than one second. This achievement is the first demonstration in the world that naturally occurring radio waves called “chorus” in space rapidly accelerate electrons in a short period of time of less than one second. This achievement was achieved using observation data from the Japanese “Arase” satellite and a new analysis method.
Chorus, also called "cosmic chirps," is a radio wave that has been observed around planets such as Jupiter and Saturn, in addition to Earth, and is thought to accelerate electrons. In this study, we analyzed how electron acceleration occurs with the generation of the chorus using a newly devised method, and revealed ultrafast electron acceleration that could not be detected using conventional averaged data.
High-energy electrons accelerated in space can cause satellite malfunctions. This discovery will contribute to the safe and secure use of space through improved accuracy in satellite design and space weather forecasting. In addition, the analysis method developed in this research can be applied to past observation data, and is expected to further elucidate the mysteries of the space environment.
The research results were published in the British scientific journal Scientific Reports on January 14, 2025.
Figure: Traces of ultrafast acceleration of electrons by the chorus discovered through observations by the Arase satellite
Associate Professor Satoshi Kasahara and Assistant Professor Kunihiro Keika of the Department of Earth and Planetary Science participated in this study.
Related links: Kyoto University, Nagoya University, National Institute of Information and Communications Technology (NICT), Tohoku University, Kanazawa University, Osaka University
Journals
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Journal name Scientific ReportsTitle of paper