土星异常十米辐射，一种由卡西尼号揭示的新型土星射电辐射。

Saturn Anomalous Myriametric Radiation, a New Type of Saturn Radio Emission Revealed by Cassini.

作者信息

Wu S Y, Ye S Y, Fischer G, Taubenschuss U, Jackman C M, O'Dwyer E, Kurth W S, Yao S, Yao Z H, Menietti J D, Xu Y, Long M Y, Cecconi B

机构信息

Department of Earth and Space Sciences Southern University of Science and Technology Shenzhen People's Republic of China.

LESIA Observatoire de Paris Université PSL CNRS Sorbonne Université Université de Paris Meudon France.

出版信息

Geophys Res Lett. 2022 Aug 28;49(16):e2022GL099237. doi: 10.1029/2022GL099237. Epub 2022 Aug 19.

DOI:10.1029/2022GL099237

PMID:36249464

原文链接:https://pmc.ncbi.nlm.nih.gov/articles/PMC9541930/

Abstract

A new radio component namely Saturn Anomalous Myriametric Radiation (SAM) is reported. A total of 193 SAM events have been identified by using all the Cassini Saturn orbital data. SAM emissions are L-O mode radio emission and occasionally accompanied by a first harmonic in R-X mode. SAM's intensities decrease with increasing distance from Saturn, suggesting a source near Saturn. SAM has a typical central frequency near 13 kHz, a bandwidth greater than 8 kHz and usually drifts in frequency over time. SAM's duration can extend to near 11 hr and even longer. These features distinguish SAM from the regular narrowband emissions observed in the nearby frequency range, hence the name anomalous. The high occurrence rate of SAM after low frequency extensions of Saturn Kilometric Radiation and the SAM cases observed during compressions of Saturn's magnetosphere suggest a special connection to solar wind dynamics and magnetospheric conditions at Saturn.

摘要

报道了一种名为土星异常万米辐射（SAM）的新型射电成分。利用卡西尼号土星轨道的所有数据，共识别出193次SAM事件。SAM辐射是L-O模式的射电辐射，偶尔伴有R-X模式的一次谐波。SAM的强度随着离土星距离的增加而降低，这表明其源靠近土星。SAM具有典型的中心频率接近13千赫，带宽大于8千赫，并且频率通常随时间漂移。SAM的持续时间可以延长到近11小时甚至更长。这些特征将SAM与在附近频率范围内观测到的常规窄带辐射区分开来，因此得名异常。土星千米辐射低频扩展后SAM的高发生率以及在土星磁层压缩期间观测到的SAM事例表明，它与土星的太阳风动力学和磁层条件存在特殊联系。