A Quantitative Study of the Homologous Flares on 2000 November 24

Autor: Yasuhiro Takei, Hiroyuki Takasaki, Ayumi Asai, Toshio Terasawa, Kazunari Shibata, Masumi Shimojo, Junko Kiyohara
Rok vydání: 2004
Předmět:
Zdroj: The Astrophysical Journal. 613:592-599
ISSN: 1538-4357
0004-637X
Popis: We present an examination of multiwavelength observations of three X-class homologous flares that occurred on 2000 November 24. By investigating the behavior of the two-ribbon flares in Hα and the ultraviolet (1600 A), we found that the temporal variation of the distance between the two ribbons shows a good correlation with the soft X-ray light curve. From this finding we can derive the relation dISXR(t)/dt ∝ Vrib(t), where ISXR(t) is the soft X-ray intensity and Vrib(t) is the separation velocity of the two ribbons. This relation is similar to the well-known empirical law, the Neupert effect. We also measured the rise time, velocity of the plasmoid/filament ejection, and separation velocity of the two ribbons for each of these homologous flares. Since the magnetic reconnection model predicts that each of these physical parameters has a dependence on the coronal magnetic field strength Bc, we derived the relative Bc between the three flares from each of the parameters. We compared the relative Bc values, which are derived from those parameters, and found that they are roughly equal. Our results successfully support the magnetic reconnection model. Moreover, the relative hard X-ray maximum intensity in each flare is consistent with the relative Bc derived above, if we assume that the hard X-ray intensity is proportional to the energy release rate as implied by the Neupert effect.
Databáze: OpenAIRE
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