Population Ratios for the Fine-Structure Ground State of O i Applicable to the Interstellar Medium
Abstract
Recent R-matrix calculations of electron excitation rates among the 2s22p4 3P fine-structure levels in O I are used to derive density-sensitive population ratios n(3P1)/n(3P2) and n(3P0)/n(3P2) for the ranges of electron and neutral hydrogen densities (ne = 10-2 - 103cm-3; nH = 0 - 1000 cm-3) applicable to H I and H II regions. The results differ significantly from those of Smeding and Pottasch and will lead to electron density estimates between 30% and a factor of 2 smaller.
- Publication:
-
The Astrophysical Journal
- Pub Date:
- October 1988
- DOI:
- 10.1086/166789
- Bibcode:
- 1988ApJ...333..806K
- Keywords:
-
- Electron States;
- Fine Structure;
- Ground State;
- H I Regions;
- H Ii Regions;
- Interstellar Gas;
- Electron Density Profiles;
- Gas Density;
- Astrophysics;
- ATOMIC PROCESSES;
- INTERSTELLAR: ABUNDANCES;
- NEBULAE: H II REGIONS;
- ULTRAVIOLET: SPECTRA