Return current effects on hard X-ray and microwave emission produced by electron beams in solar flares.
Abstract
Electron beam distribution functions, found from a joint solution of the kinetic and electric current conservation equations for an electron beam in converging magnetic field, are used for the calculations of resulting hard X-ray bremsstrahlung fluxes for beams with different parameters. X-ray fluxes are shown to have non-monotonic energy distributions with the flux depression (dip) at 20-25keV, caused by the effect of an electric current on the beam electron distributions, with spectral indices before the dip higher by 1-1.5 units than after it. These effects can explain surprisingly well the observational discrepancies in spectral indices and total energy fluxes, detected from SMM and Yohkoh hard X-ray observations in different energy bands.
- Publication:
-
Astronomy and Astrophysics
- Pub Date:
- April 1997
- Bibcode:
- 1997A&A...320L..13Z
- Keywords:
-
- SUN: FLARES;
- SUN: X-RAYS;
- PLASMAS;
- ELECTRON BEAMS