Details

Autor(en) / Beteiligte

• YU, SIJIE
• Yan, Yihua
• Tan, Baolin

Titel

RELAXATION OF MAGNETIC FIELD RELATIVE TO PLASMA DENSITY REVEALED FROM MICROWAVE ZEBRA PATTERNS ASSOCIATED WITH SOLAR FLARES

Ist Teil von

• The Astrophysical journal, 2012-12, Vol.761 (2), p.1-9

Ort / Verlag

United States

Erscheinungsjahr

2012

Link zum Volltext

Quelle

EZB Free E-Journals

Beschreibungen/Notizen

• It is generally considered that the emission of microwave zebra pattern (ZP) structures requires high density and high temperature, which is similar to the situation of the flaring region where primary energy is released. Therefore, a parameter analysis of ZPs may reveal the physical conditions of the flaring source region. This work investigates the variations of 74 microwave ZP structures observed by the Chinese Solar Broadband Radio Spectrometer (SBRS/Huairou) at 2.6-3.8 GHz in nine solar flares, and we find that the ratio between the plasma density scale height L sub(N) and the magnetic field scale height L sub(B) in emission sources displays a tendency to decrease during the flaring processes. The ratio L sub(N)/L sub(B) is about 3-5 before the maximum of flares. It decreases to about 2 after the maximum. The detailed analysis of three typical X-class flares implies that the variation of L sub(N)/L sub(B) during the flaring process is most likely due to topological changes of the magnetic field in the flaring source region, and the stepwise decrease of L sub(N)/L sub(B) possibly reflects the magnetic field relaxation relative to the plasma density when the flaring energy is released. This result may also constrain solar flare modeling to some extent.