Volume 471, Number 2, August IV 2007
|Page(s)||705 - 709|
|Published online||25 May 2007|
Correlation and asymmetry between solar flare hard X-ray footpoints: a statistical study
Department of Astronomy, Nanjing University, Nanjing 210093, PR China e-mail: email@example.com
Accepted: 23 April 2007
Aims.We study the correlation and asymmetry between solar flare hard X-ray footpoint time profiles that can be used to constrain the energy release and particle acceleration processes in solar flares.
Methods.We perform a statistical analysis of correlations and asymmetries of hard X-ray footpoints for 29 solar flares that were observed by the Reuven Ramaty High Energy Solar Spectroscopic Imager (RHESSI) in 2002–2005. Using the CLEAN method, we derive the hard X-ray images and then extract light curves for each footpoint. We decompose the hard X-ray light curves into slowly-varying components and fast-varying components using the Fourier method and check their correlations separately.
Results.Our analysis indicates that the asymmetry between hard X-ray footpoints is a ubiquitous feature in solar flares. However, in most asymmetric cases, the correlations between the light curves of the two footpoints remain high. In particular, the correlation coefficients between the slowly-varying components are significantly higher than those between the fast-varying components. We discuss the causes and implications of the asymmetries and correlations between hard X-ray footpoints.
Key words: Sun: flares / Sun: magnetic fields / Sun: X-rays, gamma rays
© ESO, 2007
Current usage metrics show cumulative count of Article Views (full-text article views including HTML views, PDF and ePub downloads, according to the available data) and Abstracts Views on Vision4Press platform.
Data correspond to usage on the plateform after 2015. The current usage metrics is available 48-96 hours after online publication and is updated daily on week days.
Initial download of the metrics may take a while.