A SKYLAB flare associated with a hard X-ray burst
Abstract
The Skylab flare of Jan. 21, 1974 has been studied as a clear example of impulsive EUV emission associated with a hard X-ray burst. The spatial characteristics and temporal behavior of the impulsive and gradual phase components are described, and the emission measure distribution in the brightest impulsive emission patch is derived and compared with the emission measure plot of the hot gradual component. The column emission measure of this patch shows a steep decrease between He II and O IV and a relatively flat distribution between O IV and Fe XIV. The impulsive behavior in the patch appears to extend in temperature only as high as Si X and Fe XIV, consistent with the impulsive enhancement being almost entirely confined to ions emitting at temperatures below one or two million degrees. The emission measure of the hot kernel in the impulsive phase spectrum is confined to temperatures greater than 1.5 million K and has steep slope between 1.5 and 8 million K.
- Publication:
-
The Astrophysical Journal
- Pub Date:
- June 1984
- DOI:
- 10.1086/162113
- Bibcode:
- 1984ApJ...281..426W
- Keywords:
-
- Solar Flares;
- Solar X-Rays;
- Ultraviolet Spectra;
- Extreme Ultraviolet Radiation;
- Helium;
- Iron;
- Line Spectra;
- Oso-7;
- Oxygen;
- Skylab Program;
- Spectroheliographs;
- Solar Physics