The Free-Free Absorption Coefficients of the Negative Helium Ion
Abstract
Free-free absorption coefficients of the negative helium ion are calculated by a phaseshift approximation, using continuum data that accurately account for electron-atom correlation and polarization. The approximation is considered to yield results within a few per cent of numerical values for wavelengths greater than 1 m, over the temperature range 1400-10080 K. These coefficients are expected to give the best current estimates of He - continuous absorption. Key words: atomic data - atomic processes - stars: atmospheres - infrared: general.
- Publication:
-
Monthly Notices of the Royal Astronomical Society
- Pub Date:
- August 1994
- DOI:
- 10.1093/mnras/269.4.871
- Bibcode:
- 1994MNRAS.269..871J