Observations of a Radio-Quiet Solar Preflare
- Author(s)
- Arnold O. Benz, Marina Battaglia, Manuel Güdel
- Abstract
The preflare phase of the flare SOL2011-08-09T03:52 is unique in its long duration, in that it was covered by the Reuven Ramaty High Energy Solar Spectroscopic Imager (RHESSI) and the Nobeyama Radioheliograph, and because it showed three well-developed soft X-ray (SXR) peaks. No hard X-rays (HXR) are observed in the preflare phase. Here we report that no associated radio emission at 17 GHz was found either, despite the higher sensitivity of the radio instrument. The ratio between the SXR peaks and the upper limit of the radio peaks is higher by more than one order of magnitude than the ratio in regular flares. The result suggests that the ratio between acceleration and heating in the preflare phase was different than in regular flares. Acceleration to relativistic energies, if any, occurred with lower efficiency.
- Organisation(s)
- Department of Astrophysics
- External organisation(s)
- Fachhochschule Nordwestschweiz , Eidgenössische Technische Hochschule Zürich
- Journal
- Solar Physics
- Volume
- 292
- No. of pages
- 8
- ISSN
- 0038-0938
- DOI
- https://doi.org/10.1007/s11207-017-1175-3
- Publication date
- 10-2017
- Peer reviewed
- Yes
- Austrian Fields of Science 2012
- 103003 Astronomy, 103004 Astrophysics
- Keywords
- ASJC Scopus subject areas
- Astronomy and Astrophysics, Space and Planetary Science
- Portal url
- https://ucrisportal.univie.ac.at/en/publications/82b88521-722c-4e17-a9d6-c16f03690880