Isolating the Footpoint Characteristics of a Solar Flare Loop

Author： Harra-Murnion L.K. Culhane J.L. Hudson H.S. Fujiwara T. Kato T. Sterling* A.C.

ISSN： 0038-0938

Source： Solar Physics, Vol.171, Iss.1, 1997-03, pp. : 103-122

Disclaimer: Any content in publications that violate the sovereignty, the constitution or regulations of the PRC is not accepted or approved by CNPIEC.

Previous Menu Next

Abstract

We analyse the physical characteristics of a C5.7 class flare which was observed on 27 September, 1993 using data from the soft X-ray telescope (SXT), the Bragg crystal spectrometer (BCS), and the hard X-ray telescope (HXT) on Yohkoh. The flare takes the form of a simple loop which is much brighter at one of its footpoints than anywhere else for a period of 2 min. During this time there is an increase in the soft X-ray fluxes, and a corresponding peak in hard X-rays. The parameters derived from the hard X-ray and soft X-ray spectra and images are assumed to be from the footpoint. This flare showed two peaks in the non-thermal velocity, the first one simultaneous with the footpoint brightening. The non-thermal velocity corresponding to these first few minutes is unusually large – by a factor of 80%, 68%, and 26% relative to the second peak in the Fexxv, Caxix, and Sxv channels respectively.