Narrowband dm-spikes and associated X-ray emission
Abstract
Narrowband dm-spikes observed in nine intervals during five solar flares (20 May 2002, 18 March 2003, 10 June 2003, 22 June 2003 and 5 August 2003) were analyzed together with the RHESSI and HXRS observations. The height scale spectra of the spikes were derived and their spectral scale index was found to be between --0.67 and --1.6 . We divided the studied events into two groups: a) the spikes observed before the soft X-ray flare maximum and, b) the spikes observed after the maximum. While the events with spikes after the flare maximum manifested no specific characteristics, we found that during the events with spikes before the flare (X-ray) maximum (10 June 2003 and 5 August 2003) the spikes were associated with relatively hard X-ray spectra (spectral index gamma was 3.0 and 3.7, respectively) and the spectral slope was increasing afterwards (the X-ray spectrum was getting softer during the event approaching the thermal equilibrium). All the observational results are discussed in frame of our model of the narrowband dm-spikes.
- Publication:
-
35th COSPAR Scientific Assembly
- Pub Date:
- 2004
- Bibcode:
- 2004cosp...35.1166F