Hostname: page-component-78c5997874-xbtfd Total loading time: 0 Render date: 2024-11-07T23:20:36.797Z Has data issue: false hasContentIssue false
  • English
  • Français

Relationship between Hard and Soft Solar X-Ray Sources Observed by OSO-7

Published online by Cambridge University Press:  14 August 2015

D. W. Datlowe  and
H. S. Hudson
D. W. Datlowe
Affiliation:
University of California, San Diego, La Jolla, Calif., U.S.A.
H. S. Hudson
Affiliation:
University of California, San Diego, La Jolla, Calif., U.S.A.

Summary

Core share and HTML view are not available for this content. However, as you have access to this content, a full PDF is available via the ‘Save PDF’ action button.

The UCSD experiment on the OSO-7 satellite has provided hard and soft X-ray observations of a large number of solar flares. Of these a sample of 123 had sufficiently large fluxes to permit analysis of their spectra (Datlowe et al., 1974). The locations of these flares upon the solar disk have been obtained by comparison with Hα flare listings. We find that the soft (5.1–6.6 keV) X-ray bursts, above a threshold of 1000 photons (cm2 s keV)–1, have a relatively flat distribution from center to limb. The frequency of occurrence of hard (20–30 keV) X-ray bursts, as normalized to the longitude distribution of the soft X-ray bursts, shows a statistically insignificant excess of 19±34% in the longitude range 80–90°. Furthermore, the limb flares exhibit a small but statistically significant spectral softening.

Type
Part 3: Solar Flares
Information
Symposium - International Astronomical Union , Volume 68: Solar X, Gamma, and EUV Radiation , 1975 , pp. 209
Copyright
Copyright © Reidel 1975 

References

Brown, J. C.: 1972, Solar Phys. 26, 459.Google Scholar
Datlowe, D. W., Elcan, M., Hudson, H. S.: 1974, Solar Phys. 35, 193.Google Scholar
Petrosian, V.: 1973, Astrophys. J. 186, 291.CrossRefGoogle Scholar
Roy, J. R. and Datlowe, D. W.: 1974, Solar Phys. 40, 165.Google Scholar
Tindo, I. P., Ivanov, V. D., Mandelstam, S. L., and Shurygin, A. I.: 1972, Solar Phys. 24, 429.Google Scholar