Hard X-ray emission during flares and changes in the photospheric magnetic field
Abstract
We study the relationship between the field changes in the photosphere and the reconnection processes in the corona by comparing the locations of abrupt permanent changes of the magnetic field during strong flares observed by the GONG and HMI instruments and hard X-ray (HXR) emission observed by RHESSI. The chromospheric HXR emission in solar flares is generally believed to mark the footprints of magnetic field lines newly reconnected in the corona. Also, the footpoint motions away from the neutral line are considered to be indicative of the reconnection occurring in arcade magnetic fields at different heights. Our analysis of six flares that occurred during the declining phase of cycle 23 shows that the strongest field changes are well correlated in space, with the HXR footprints moving away from the neutral line in later stages of the flare. The majority of field changes and HXR footpoints are spatio-temporally related but not simultaneous. We will also compare changes in the HMI vector magnetic field measurements with the location and evolution of flare footpoints and discuss possible implications for topology of the magnetic field at the reconnection site in the corona.
- Publication:
-
AAS/Solar Physics Division Abstracts #44
- Pub Date:
- July 2013
- Bibcode:
- 2013SPD....44...73B