Footpoint versus loop-top hard X-ray emission sources in solar flares

M. Tomczak; T. Ciborski

doi:10.1051/0004-6361:20066115

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arXiv · astro-ph/0610409

Footpoint versus loop-top hard X-ray emission sources in solar flares

M. Tomczak·T. Ciborski

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Abstract

The hard X-ray flux ratio R of the footpoint sources to the loop-top source has been used to investigate non-thermal electron trapping and precipitation in solar flares. Considering the mission-long Yohkoh Hard X-ray Telescope database, from which we selected 117 flares, we investigated a dependence of the ratio R on flare loop parameters like height h and column depth N. We used non-thermal electron beams as a diagnostic tool for magnetic convergence. The ratio R decreases with h which we interpret as an effect of converging field geometry. Two branches seen in the R-h diagram suggest that in the solar corona two kinds of magnetic loops can exist: a more-converged ones that are more frequent (above 80%) and less-converged loops that are less frequent (below 20%). A lack of correlation between the ratio R and N can be due to a more complex configuration of investigated events than seen in soft X-rays. Obtained values of the magnetic mirror ratio are consistent with previous works and suggest a strongly nonpotential configuration. Further investigation including RHESSI data is needed to verify our results.

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BibTeX RIS

M. Tomczak, T. Ciborski. 2006-10-13. Footpoint versus loop-top hard X-ray emission sources in solar flares. https://doi.org/10.1051/0004-6361%3A20066115

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