Sign on

SAO/NASA ADS Astronomy Abstract Service


· Find Similar Abstracts (with default settings below)
· Full Refereed Journal Article (PDF/Postscript)
· Full Refereed Scanned Article (GIF)
· Table of Contents
· References in the article
· Citations to the Article (62) (Citation History)
· Refereed Citations to the Article
· Also-Read Articles (Reads History)
·
· Translate This Page
Title:
Millimeter, microwave, hard X-ray, and soft X-ray observations of energetic electron populations in solar flares
Authors:
Kundu, M. R.; White, S. M.; Gopalswamy, N.; Lim, J.
Affiliation:
AA(University of Maryland, College Park, MD, US), AB(University of Maryland, College Park, MD, US), AC(University of Maryland, College Park, MD, US), AD(University of Maryland, College Park, MD, US)
Publication:
Astrophysical Journal Supplement Series (ISSN 0067-0049), vol. 90, no. 2, p. 599-610 (ApJS Homepage)
Publication Date:
02/1994
Category:
Solar Physics
Origin:
STI
NASA/STI Keywords:
Electron Emission, Gamma Ray Astronomy, Millimeter Waves, Solar Flares, Solar X-Rays, Bremsstrahlung, Energy Spectra, X Ray Spectroscopy
DOI:
10.1086/191881
Bibliographic Code:
1994ApJS...90..599K

Abstract

We present comparisons of multiwavelength data for a number of solar flares observed during the major campaign of 1991 June. The different wavelengths are diagnostics of energetic electrons in different energy ranges: soft X-rays are produced by electrons with energies typically below 10 keV, hard X-rays by electrons with energies in the range 10-200 keV, microwaves by electrons in the range 100 keV-1 MeV, and millimeter-wavelength emission by electrons with energies of 0.5 MeV and above. The flares in the 1991 June active period were remarkable in two ways: all have very high turnover frequencies in their microwave spectra, and very soft hard X-ray spectra. The sensitivity of the microwave and millimeter data permit us to study the more energetic (greater than 0.3 MeV) electrons even in small flares, where their high-energy bremsstrahlung is too weak for present detectors. The millimeter data show delays in the onset of emission with respect to the emissions associated with lower energy electrons and differences in time profiles, energy spectral indices incompatible with those implied by the hard X-ray data, and a range of variability of the peak flux in the impulsive phase when compared with the peak hard X-ray flux which is two orders of magnitude larger than the corresponding variability in the peak microwave flux. All these results suggest that the hard X-ray-emitting electrons and those at higher energies which produce millimeter emission must be regarded as separate populations. This has implications for the well-known 'number problem' found previously when comparing the numbers of non thermal electrons required to produce the hard X-ray and radio emissions.

Printing Options

Print whole paper
Print Page(s) through

Return 600 dpi PDF to Acrobat/Browser. Different resolutions (200 or 600 dpi), formats (Postscript, PDF, etc), page sizes (US Letter, European A4, etc), and compression (gzip,compress,none) can be set through the Printing Preferences



More Article Retrieval Options

HELP for Article Retrieval


Bibtex entry for this abstract   Preferred format for this abstract (see Preferences)

  New!

Find Similar Abstracts:

Use: Authors
Title
Keywords (in text query field)
Abstract Text
Return: Query Results Return    items starting with number
Query Form
Database: Astronomy
Physics
arXiv e-prints