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The observation of 10–50 KeV solar flare X-rays by the OGO satellites and their correlation with solar radio and energetic particle emission

Published online by Cambridge University Press:  14 August 2015

R. L. Arnoldy ,
S. R. Kane  and
J. R. Winckler
R. L. Arnoldy
Affiliation:
School of Physics and Astronomy, University of Minnesota, Minneapolis, Minn., U.S.A.
S. R. Kane
Affiliation:
School of Physics and Astronomy, University of Minnesota, Minneapolis, Minn., U.S.A.
J. R. Winckler
Affiliation:
School of Physics and Astronomy, University of Minnesota, Minneapolis, Minn., U.S.A.

Abstract

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More than 70 cases have been observed of energetic solar flare X-ray bursts by large ionization chambers on the OGO satellites in space. The ionization chambers have an energy range between 10 and 50 KeV for X-rays and are also sensitive to solar protons and electrons. A study has been made of the X-ray microwave relationship, and it is found that the total energy released in the form of X-rays between 10 and 50 KeV is approximately proportional to the peak or total energy simultaneously released in the form of microwave emission. For a given burst the rise time, decay time and total duration are similar for the 10–50 KeV X-rays and the 3 to 10 cm radio emission. Roughly exponential decay phases are observed for both emissions with time constants between 1 and 10 min. All 3 or 10 cm radio bursts with peak intensity greater than 80 solar flux units are accompanied by an X-ray burst greater than 3 × 10−7 ergs cm−2 sec−1 peak intensity. The probability of detecting such X-ray events is low unless the radio spectrum extends into the centimetric range of wavelengths. The best correlation between cm-λ and energetic X-rays is observed for the first event in a flare. Subsequent structure and second bursts may not correspond even when the radio emission is rich in the microwave component. The mechanism for the energetic X-rays is shown to be bremsstrahlung probably of fast electrons on a cooler plasma. If the radio emission is assumed to be synchrotron radiation then a relationship is developed between density and magnetic field which meets the observed quantitative results. One finds, on the average, that 5 × 10−54 joules m−2 (CPS)−1 of microwave energy at the Earth are required per electron at the Sun to provide the radio emission for the various events.

A strong correlation between interplanetary solar flare electrons observed by satellite and X-ray bursts is shown to exist. This correlation is weak for solar proton events. One may infer a strong propagation asymmetry for solar flare electrons along the spiral interplanetary magnetic field.

Type
Part VI: Transient Phenomena
Information
Symposium - International Astronomical Union , Volume 35: Structure and Development of Solar Active Regions , 1968 , pp. 490 - 509
Copyright
Copyright © Reidel 1968 

References

Acton, L.W. (1964) Nature, 204, 64–65.CrossRefGoogle Scholar
Anderson, K.A., Winckler, J.R. (1962) J. geophys. Res., 67, 4103–4117.CrossRefGoogle Scholar
Arnoldy, R.L., Kane, S.R., Winckler, J.R. (1967a) Solar Phys., 2, 171.CrossRefGoogle Scholar
Arnoldy, R.L., Kane, S.R., Winckler, J.R. (1967b) University of Minnesota Technical Report CR-97. Also, to be published in Astrophysical Journal, February, 1968.Google Scholar
Bruzek, A. (1964) AAS-NASA Symposium on the Physics of Solar Flares, Scientific and Technical Information Division, NASA, Washington, D.C., 301–322.Google Scholar
Chubb, T.A., Kreplin, R.W., Friedman, H. (1966) J. geophys. Res., 71, 3611–3622.CrossRefGoogle Scholar
Cline, T.L., Holt, S.S., Hones, E.W. Jr. (1967) Goddard Tech. Report X-611-67-348, 1965 Cospar Symposium, London.Google Scholar
De Jager, C. (1959) in Handbuch der Physik, Springer-Verlag, Heidelberg, LII, p. 205.Google Scholar
Ellison, M.A., McKenna, S.P., Reid, J.H. (1961) Dunsink Obs. Publ., 1, 75.Google Scholar
Elwert, G. (1961) J. geophys. Res., 66, 391–401.CrossRefGoogle Scholar
Friedman, H. (1964) AAS-NASA Symposium on the Physics of Solar Flares, Scientific and Technical Information Division, NASA, Washington, D.C., 147–157.Google Scholar
Hofmann, D.J., Winckler, J.R. (1963) J. geophys. Res., 68, 2067–2099.CrossRefGoogle Scholar
Kane, S.R., Pfitzer, K.A., Winckler, J.R. (1966) University of Minnesota Technical Report CR-87. Google Scholar
Koch, H.W., Motz, J.W. (1959) Reviews of Modern Physics, 31, 920–955.CrossRefGoogle Scholar
Kundu, M.K. (1965) Solar Radio Astronomy, Interscience Publishers, New York, pp. 530–534.Google Scholar
Lin, R.P., Anderson, K.A. (1967) Solar Phys., 1, 446–464.CrossRefGoogle Scholar
Moreton, G.E. (1964) AAS-NASA Symposium on the Physics of Solar Flares, Scientific and Technical Information Division, NASA, Washington, D.C., 209–212.Google Scholar
Peterson, L.E., Winckler, J.R. (1959) J. geophys. Res., 64, 697–701.CrossRefGoogle Scholar
Shklovsky, J. (1964) Nature, 202, 275.CrossRefGoogle Scholar
Shklovsky, I.S. (1965) Soviet Astr. – AJ, 8, 538–543.Google Scholar
Stein, W.A., Ney, E.P. (1963) J. geophys. Res., 68, 65–81.CrossRefGoogle Scholar
Takakura, T. (1960) Publ. astr. Soc. Japan, 12, 326–346.Google Scholar
Takakura, T. (1963) private communication.Google Scholar
Takakura, T., Kai, K. (1966) Publ. astr. Soc. Japan, 18, 57–76.Google Scholar
Van Allen, J.A., Krimigis, S.M. (1965) J. geophys. Res., 70, 5737–5751.CrossRefGoogle Scholar
Vette, J.I., Casal, F.G. (1961) Phys. Rev. Lett., 6, 334–336.CrossRefGoogle Scholar
Winckler, J.R. (1963) AAS-NASA Symposium on the Physics of Solar Flares, Scientific and Technical Information Division, NASA, Washington, D.C., 117–127.Google Scholar
Winckler, J.R., May, T.C., Masley, A.J. (1961) J. geophys. Res., 66, 316.CrossRefGoogle Scholar
Zheleznyakov, V.V. (1965) Soviet Physics – Astronomy, 9, 73–76.Google Scholar