ATTENUATION OF CORONAL MAGNETIC FIELDS IN SOLAR MICROWAVE BURSTS

Journal Article · Wed Jun 10 00:00:00 EDT 2015 · Astrophysical Journal

DOI:https://doi.org/10.1088/0004-637X/806/1/12· OSTI ID:22522343

Huang, Guangli; Li, Jianping; Song, Qiwu; Huang, Yu ^[1]; Tan, Baolin ^[2]; Wu, Zhao ^[3]

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1. Purple Mountain Observatory, Chinese Academy of Sciences (CAS), Nanjing, 210008 (China)
2. Key Laboratory of Solar Activities, CAS, Beijing, 100012 (China)
3. Institute of Space Sciences and School of Space Science and Physics, Shandong University, Weihai 264209 (China)

Based on the observed data by the Nobeyama Radio Observatory and the nonthermal gyrosynchrotron theory, the calculated magnetic field in a loop-like radio source of the 2001 October 23 flare attenuates from hundreds to tens of Gauss, except in the region with very weak magnetic fields. Meanwhile, the viewing angle between the magnetic field and line of sight has a similar attenuation from tens to around ten degrees, implying that the transverse magnetic component attenuates much faster than the longitudinal one. All of these results can be understood by the magnetic energy release process in solar flares. Moreover, the column density of nonthermal electrons decreases from 10{sup 9−10} to 10{sup 7−8} cm{sup −2} during the flare, except in the region with very weak magnetic fields, where its value is larger than that with strong magnetic fields due to the mirroring effect. The calculated error and harmonic number of gyrofrequency better suit the region with strong magnetic fields.

• OSTI ID: 22522343
• Journal Information: Astrophysical Journal, Vol. 806, Issue 1; Other Information: Country of input: International Atomic Energy Agency (IAEA); ISSN 0004-637X
• Country of Publication: United States
• Language: English

Related Subjects

79 ASTROPHYSICS
COSMOLOGY AND ASTRONOMY
ATTENUATION
COSMIC RADIO SOURCES
DENSITY
GYROFREQUENCY
MAGNETIC FIELDS
MICROWAVE RADIATION
SOLAR FLARES
SOLAR RADIO BURSTS
SUN