Interpretation of X-Ray Photograph of the Sun.
Abstract
An X-ray picture of the sun was obtained on April 19,1960, using pinhole-camera photography. Photometric analysis of the picture has shown that at least 75 per cent of the X-radiation passed by the pinhole window material emanated from condensations in the lower corona localixed above CaK plages. The "X-ray plages" appear to be of smaller dimension than the corresponding calcium plages. A strong correlation exists between the distribution of sources of X-ray emission and decimeter wave emission. When allowance is made for the transmission of the camera window material and the spectral sensitivity of the photographic film, it is estimated that the solar X-ray flux (0-60 A) at the earth was about 0.3 erg assuming a Planckian solar X-ray spectrum characterized by a temperature of 1060 K. There is evidence for only a small amount of limb brightening in the non-plage background emission. The measured emission extended to about 43000 km beyond the optical limb.
- Publication:
-
The Astrophysical Journal
- Pub Date:
- January 1963
- DOI:
- 10.1086/147479
- Bibcode:
- 1963ApJ...137....3B