A simplified thermal continuum functionfor the X-ray emission from coronal plasmas
Abstract
At temperatures below x io6 0K, the free-bound process makes an increasingly significant contribution to the total continuum flux. While the free-free spectrum may be represented by a relatively simple expression, a detailed calculation of the spectrum requires a lengthy summation process over all the ionization stages and levels of the abundant coronal ions. A simple empirical expression is presented which gives the magnitude and spectral slope of the free-bound contribution over the energy interval - for the temperature range 4 2ooxIo60K. This expression gives results that agree to better than 15 per cent with more detailed calculations of the thermal continuous spectrum.
- Publication:
-
Monthly Notices of the Royal Astronomical Society
- Pub Date:
- 1970
- DOI:
- 10.1093/mnras/151.1.141
- Bibcode:
- 1970MNRAS.151..141C