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De-occultation x-ray events of 2 December, 1967

Zirin, Harold and Ingham, William and Hudson, Hugh and McKenzie, David (1969) De-occultation x-ray events of 2 December, 1967. Solar Physics, 9 (2). pp. 269-277. ISSN 0038-0938. doi:10.1007/bf02391648.

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A flare rising from behind the solar limb was recorded simultaneously by the UCSD X-ray detector on OSO-III (7.7–200 keV) and the Caltech photoheliograph on Robinson Laboratory roof (Hα). The de-occultation gives excellent spatial resolution of the X-ray source. Spectra suggest that the material was already heated to 27 000 000° and that the increase in flux was due to the de-occultation. The flux rise to maximum was proportional to the apparent area. The uniformity of this rise shows that there was no special kernel of emission. Comparison of the deduced volume with the bremsstrahlung formula gives a density of about 10¹⁰ for the 27 000 000° component of the flare; this is confirmed by consideration of the maximum possible coulomb braking. The actual decay is more likely by escape rather than coulomb braking.

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Hudson, Hugh0000-0001-5685-1283
Additional Information:© 1969 Kluwer Academic Publishers. Provided by the NASA Astrophysics Data System. Received 11 April 1969; Issue Date October 1969. This work was supported by the National Aeronautics and Space Administration under grant NASA NGR 05 002 034, and the National Science Foundation under Grant 1472 (H.Z. and W.I.) and by NASA Contract NAS5-3177 (H.H. and D.M.). We wish to thank Prof. L. E. Peterson and Mr. D. A. Schwartz for encouragement and valuable suggestions.
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NASANGR 05 002 034
Issue or Number:2
Record Number:CaltechAUTHORS:20200701-073803862
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Official Citation:Zirin, H., Ingham, W., Hudson, H. et al. De-occultation x-ray events of 2 December, 1967. Sol Phys 9, 269–277 (1969).
Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:104177
Deposited By: Tony Diaz
Deposited On:01 Jul 2020 17:18
Last Modified:16 Nov 2021 18:29

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