High resolution microwave and X-ray observations of solar flares
Abstract
This paper presents an analysis of high spatial resolution observations of 18 weak flares, carried out during the Solar Maximum Year in the microwave range, H-alpha, and soft X-rays, together with observations of the associated hard X-ray emission and the photospheric magnetic field. This combination of observations made it possible to obtain a picture of the flare geometry and the relative position of the various emissions, to study the change of the geometry during the flare, to estimate the electron temperature and emission measure of the thermal plasma, and to compute the contribution of the free-free process in the microwave emission. Results are interpreted as evidence for the presence of energetic electrons even in the post-burst phase of some flares. There was also found a clear case of homologous radio and X-ray bursts, one case of foot-point expansion with a relative velocity of 20 km/s at 6.16 cm, as well as some evidence of triggering of flares by disturbances moving with a velocity of 5000-13,000 km/s.
- Publication:
-
Astronomy and Astrophysics
- Pub Date:
- April 1988
- Bibcode:
- 1988A&A...195..290A
- Keywords:
-
- High Resolution;
- Microwaves;
- Solar Flares;
- Solar Spectra;
- Solar X-Rays;
- X Ray Spectra;
- Coronal Loops;
- H Alpha Line;
- Solar Maximum Mission;
- Solar Radio Emission;
- Very Large Array (Vla);
- Solar Physics