Calculations of Level Populations for the Low Levels of Hydrogenic Ions in Gaseous Nebulae
Open Access
- 1 September 1971
- journal article
- Published by Oxford University Press (OUP) in Monthly Notices of the Royal Astronomical Society
- Vol. 153 (4), 471-490
- https://doi.org/10.1093/mnras/153.4.471
Abstract
The level populations, b nl of hydrogen and singly ionized helium are calculated making full allowance for collisional redistribution of angular momentum and energy. In many cases the l -states are not populated statistically. Intensities of the most important line series are presented for $n\,\leqslant\,40$ and for a wide range of electron temperatures and electron densities. Calculated relative intensities in the spectra of H I are compared with observed intensities in the planetary nebula NGC 7662. The agreement with the photoelectric observations is good, but there is poor agreement with the photographic observations.