Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
10694996 | Advances in Space Research | 2005 | 10 Pages |
Abstract
Coronal hard X-ray (HXR) sources were discovered by the Yohkoh HXT telescope in about two dozen limb flares: Impulsive and gradual ones. On the basis of HXT data, we investigated the spatial evolution of coronal sources. Slow ascending motions of sources are seen in several flares. In five events, it was possible to estimate the velocity of the upward motion with values between 10 and 30Â km/s. We present these observational results and conclude that coronal source motions should be studied statistically using the RHESSI high-resolution HXR imaging data. We discuss the possibility that coronal HXR emission is generated as bremsstrahlung of the fast electrons accelerated in collapsing magnetic traps due to joint action of the Fermi-type first-order mechanism and betatron acceleration.
Related Topics
Physical Sciences and Engineering
Earth and Planetary Sciences
Space and Planetary Science
Authors
B.V. Somov, T. Kosugi, S.A. Bogachev, S. Masuda, T. Sakao,