Excitation of extraordinary modes inside the source of Saturn's kilometric radiation

Ning, Hao1,2,4; Chen, Yao1,2; Li, Chuanyang1,2; Ye, Shengyi3; Kuznetsov, Alexey4; Wu, Siyuan3

2023-10-11

10.1051/0004-6361/202347149

ASTRONOMY & ASTROPHYSICS   Impact Factor & Quartile

0004-6361

1432-0746

The electron cyclotron maser instability (ECMI) of extraordinary mode waves was investigated with the parameters observed in Saturn's kilometric radiation (SKR) sources. Previous studies employed simplified dispersion relations, and did not consider the excitation of the relativistic (R) mode. This mode is introduced by considering the relativistic effect in plasmas consisting of both cold and hot electrons. Using particle-in-cell simulations, we investigated the excitation of R and X modes based on the measured data. Using the reported value of the density ratio of energetic to total electrons n(e)/n(0) = 24%, the most unstable mode is the R mode. The escaping X-mode emissions are amplified only if the energetic electrons are dominant with n(e)/n(0) >= 90%. For these cases, only the X mode is excited and the R mode disappears due to its strong coupling. The results are well in line with the linear kinetic theory of ECMI. The properties of both the R and X modes are consistent with the observed SKR emissions. This raises questions about the nature of the measured electric field fluctuations within "presumed" SKR sources. The study provides new insights into the ECMI process relevant to SKR emission mechanisms.

planets and satellites: gaseous planets radio continuum: planetary systems masers waves plasmas methods: numerical

SCI

English

NI Journal Papers

Others

NSFC["11973031","12203031","12103029"] ; China Postdoctoral Science Foundation[2022TQ0189] ; Natural Science Foundation of Shandong Province[ZR2021QA033]

Astronomy & Astrophysics

Astronomy & Astrophysics

WOS:001084576600001

EDP SCIENCES S A

SPACE SCIENCE

Web of Science

1.Shandong Univ, Inst Frontier & Interdisciplinary Sci, Qingdao 266237, Shandong, Peoples R China
2.Shandong Univ, Inst Space Sci, Jinan 264209, Shandong, Peoples R China
3.Southern Univ Sci & Technol, Dept Earth & Space Sci, Shenzhen, Guangdong, Peoples R China
4.Inst Solar Terr Phys, Irkutsk 664033, Russia

Ning, Hao,Chen, Yao,Li, Chuanyang,et al. Excitation of extraordinary modes inside the source of Saturn's kilometric radiation[J]. ASTRONOMY & ASTROPHYSICS,2023,678.

Ning, Hao,Chen, Yao,Li, Chuanyang,Ye, Shengyi,Kuznetsov, Alexey,&Wu, Siyuan.(2023).Excitation of extraordinary modes inside the source of Saturn's kilometric radiation.ASTRONOMY & ASTROPHYSICS,678.

Ning, Hao,et al."Excitation of extraordinary modes inside the source of Saturn's kilometric radiation".ASTRONOMY & ASTROPHYSICS 678(2023).