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Comments on X-rays emitted by the sun

Published online by Cambridge University Press:  14 August 2015

John C. Lindsay*
Affiliation:
Goddard Space Flight Center Greenbelt, Maryland, U.S.A.

Abstract

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Observations from the first Orbiting Solar Observatory have set an upper limit of 3.40 ± 0.95 photons/cm2.s for the 20–100 keV X-ray flux from the “quiet” Sun. Eight impulsive and short-lived 20–100 keV X-ray bursts were observed which were associated with optical flares and cm radio bursts. The 2–8 Å X-ray flux from the “quiet” Sun was observed to be associated with plage groups on the Sun. The intensity for this 2–8 Å X-radiation was found to be quite variable, changes of 5% being observed almost hourly.

A partir des observations obtenues à bord du premier satellite O. S. O., on peut fixer une limite supérieure de 3,40 ± 0,95 photons/cm2.s au flux de rayons X d'énergie comprise entre 20 et 100 keV émis par le Soleil «calme». On a enregistré huit sursauts brefs, à montée rapide, associés à des éruptions optiques et à des sursauts centimétriques. Le flux de rayons X de 2 à 8 Å semble provenir des plages. L'intensité de ce dernier rayonnement est très variable, les variations pouvant atteindre 5 % par heure.

Резюме

Резюме

Исходя из наблюдений полученных на борту первого спутника О. S. О., можно установить верхний предел в 3,40 ± 0,96 фотонов/см2 с для потоков лучей X с энергией заключенной между 20 и 100 кэв, излучаемых спокойным Солнцем. Зарегистрированы восемь коротких всплесков, с быстрым подъёмом, связанных с оптическими вспышками и с сантиметровыми всплесками. Поток лучей X от 2 до 8 Â по-видимому происходит из краев. Интенсивность этого последнего излучения очень переменна, изменения будучи в состоянии достигать 5 % за час.

Type
Session II. X and γ Radiation : The Sun
Copyright
Copyright © CNRS 1965 

References

1. Frost, K. J., 1964, Comments on High Energy X-ray Bursts Observed by OSO-1, AAS-NASA Symposium on the Physics of Solar Flares. NASA SP-50, pp. 139143.Google Scholar
2. Moreton, G. E., 1964, The Association of Bremsjstrahlung X-rays with Explosive Flares, AAS-NASA Symposium on the Physics of Solar Flares. NASA SP-50, pp. 209212.Google Scholar
3. White, W. A., Solar X-rays; A Comparison with Microwave Radiation, AAS-NASA Symposium on the Physics of Solar Flares. NASA SP-50, pp. 131137.Google Scholar
4. Giacconi, R. and Lindsay, J. C., To be published.Google Scholar