Astronomy and Astrophysics – Astronomy
Scientific paper
Oct 1994
adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=1994soph..154..317u&link_type=abstract
Solar Physics (ISSN 0038-0938), vol. 154, no. 2, p. 317-334
Astronomy and Astrophysics
Astronomy
10
Millimeter Waves, Plasma Diagnostics, Solar Flares, Solar Spectra, Solar X-Rays, Space Plasmas, Spaceborne Astronomy, X Ray Astronomy, Bremsstrahlung, Chromosphere, Emission Spectra, Gamma Ray Astronomy, Goes Satellites, Stellar Models
Scientific paper
To compare mm-wave and X-ray diagnostics of solar flare plasma, five flares observed in 1980-1991 in Metsaehovi at 22 and 37 GHz and with GOES, Solar Maximum Mission (SMM), and Gamma Ray Observatory (GRO) are studied. The first impulsive peak of the mm-wave bursts under investigation coincides in time with hard X-ray emission. The second gradual component in mm-wave emission coincides with the maximum of the soft X-ray emission measure. The bremsstrahlung mm-wave radiation from hot chromospheric plasma and gyrosynchrotron radiation driven by common population of superthermal electrons are calculated. It is shown that for mm-wave events with the first peak intensity less than or equal 100 s.f.u., the thermal bremsstrahlung is more important than the gyrosynchrotron emission. The total energy of fast electrons deduced from the first peak of mm-wave bursts is one to two orders of magnitude less than that determined from the hard X-ray emission in the approximation of a thick-target nonthermal model. That can testify in favor of the hybrid thermal/nonthermal model proposed by Holman and Benka (1992). The emission measure and the energy of evaporated plasma using both mm-wave and soft X-ray data are also determined. For events investigated here the energy of evaporated chromospheric plasma is larger than the total energy of fast electron beams. We have concluded that, for evaporation, additional energy release in the chromosphere is needed. The possibility of such energy release in the framework of an advanced circuit model for solar flares is discussed.
Bakhareva N. M.
Stepanov Alexander V.
Urpo Seppo
Zaitsev Valerii V.
No associations
LandOfFree
Comparison of mm-wave and X-ray diagnostics of flare plasma does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.
If you have personal experience with Comparison of mm-wave and X-ray diagnostics of flare plasma, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Comparison of mm-wave and X-ray diagnostics of flare plasma will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-1073113