Magnetic reconnection rate and spectral index for two double-ribbon flares

作者：Ning, Zongjun^*

来源：Astrophysics and Space Science, 2008, 314(1-3): 137-143.

DOI：10.1007/s10509-008-9749-z

• sun : flares
• sun : UV radiation
• sun : X-rays
• sun : gamma-rays

We explore the correlations between the inferred reconnection rate and hard X-ray spectral hardness for two double-ribbon flares on 2003 November 1 and 2005 May 17 in this paper. The magnetic reconnection rate of phi(rec) is derived from the time rate of change of the product between the normal magnetic field and the newly brightened ribbon area of TRACE 1600 angstrom observations. And the spectral index of gamma is derived from RHESSI hard X-ray data. Both events show a soft-hard-soft spectral behaviour in the rise-peak-decay phases. An anti-correlated behaviour is found between the time evolution of reconnection rate and spectral index. From the regression analysis, we obtain a negative power-law dependence and quantify the relationship between these two quantities. This is consistent with the simulation results before, and further confirms the importance of magnetic reconnection for the electron acceleration in solar flares.

• 出版日期2008-4
• 单位中国科学院紫金山天文台