Long-Period Oscillations of Sunspots by NoRH and SSRT Observations

被引：15

作者：

Bakunina, Irina A. ^{[1
,2
,3
]}

Abramov-Maximov, Vladimir E. ^{[3
]}

Nakariakov, Valery M. ^{[3
,4
,5
]}

Lesovoy, Sergei V. ^{[6
]}

Soloviev, Alexander A. ^{[3
]}

Tikhomirov, Yurii V. ^{[2
]}

Melnikov, Victor F. ^{[2
,3
]}

Shibasaki, Kiyoto ^{[7
]}

Nagovitsyn, Yurii A. ^{[3
]}

Averina, Elena L. ^{[1
]}

机构：

[1] Natl Res Univ, Higher Sch Econ, Nizhnii Novgorod 603155, Russia

[2] Radiophys Res Inst NIRFI, Nizhnii Novgorod 603950, Russia

[3] Russian Acad Sci, Cent Astron Observ Pulkovo, St Petersburg 196140, Russia

[4] Univ Warwick, Dept Phys, Coventry CV4 7AL, W Midlands, England

[5] Kyung Hee Univ, Sch Space Res, Yongin 446701, Gyeonggi, South Korea

[6] RAS SB, Inst Solar Terr Phys, Irkutsk 664033, Russia

[7] Natl Inst Nat Sci, Natl Astron Observ Japan, Nobeyama Solar Radio Observ, Minamisa Ku, Minamimaki, Nagano 3841305, Japan

来源：

PUBLICATIONS OF THE ASTRONOMICAL SOCIETY OF JAPAN | 2013年 / 65卷

基金：

俄罗斯基础研究基金会; 欧洲研究理事会;

关键词：

Sun: oscillations; Sun: radio radiation; Sun: sunspots; CHROMOSPHERE; EMISSION; WAVES; FLOWS; SUN;

D O I：

10.1093/pasj/65.sp1.S13

中图分类号：

P1 [天文学];

学科分类号：

0704 ;

摘要：

Long-term oscillations of microwave emission generated in sunspot magnetospheres are detected with the Nobeyama Radioheliograph (NoRH) at a frequency of 17 GHz, and the Siberian Solar Radio Telescope (SSRT) at 5.7 GHz. Significant periodicities in the range of 22-170 min are found in the variation of the emission intensity, polarisation and the degree of circular polarisation. Periods of the oscillations are not stable: they are different in different sunspots and in the same sunspot on different days. A cross-correlation analysis shows the presence of common significant periods in both NoRH and SSRT data. The cross-correlation coefficients are typically lower than 0.5, which can be attributed to the different heights of the emission formation, and different mechanisms for the emission generation (gyroresonance and thermal bremstrahlung at 17 GHz, and pure gyroresonance at 5.7 GHz). The observational results are consistent with the global sunspot oscillation model.

引用

页数：12

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