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(Fe II) emission from high-density regions in the Orion Nebula
- Source :
- Astrophysical Journal, Part 2 - Letters. 432(2)
- Publication Year :
- 1994
- Publisher :
- United States: NASA Center for Aerospace Information (CASI), 1994.
-
Abstract
- Direct spectroscopic evidence of high-density regions in the Orion Nebula, N(sub e) approximately equals 10(exp 5)-10(exp 7)/cu cm, is obtained from the forbidden optical and near-IR (Fe II) emission lines, using new atomic data. Calculations for level populations and line ratios are carried out using 16, 35, and 142 level collisional-radiative models for Fe II. Estimates of Fe(+) abundances derived from the near-infrared and the optical line intensities are consistent with a high density of 10(exp 6)/cu cm in the (Fe II) emitting regions. Important consequences for abundance determinations in the nebula are pointed out.
- Subjects :
- Astronomy
Subjects
Details
- Language :
- English
- ISSN :
- 0004637X
- Volume :
- 432
- Issue :
- 2
- Database :
- NASA Technical Reports
- Journal :
- Astrophysical Journal, Part 2 - Letters
- Notes :
- NAGW-3315, , NSF PHY-91-15057, , NSF AST-91-23547
- Publication Type :
- Report
- Accession number :
- edsnas.19950040581
- Document Type :
- Report
- Full Text :
- https://doi.org/10.1086/187530