Sign on

SAO/NASA ADS Astronomy Abstract Service

· Find Similar Abstracts (with default settings below)
· Electronic Refereed Journal Article (HTML)
· Full Refereed Journal Article (PDF/Postscript)
· On-line Data
· References in the article
· Citations to the Article (58) (Citation History)
· Refereed Citations to the Article
· SIMBAD Objects (17)
· Associated Articles
· Reads History
·
· Translate This Page
Title:
Faint Emission Lines and Temperature Fluctuations in M8
Authors:
Esteban, César; Peimbert, Manuel; Torres-Peimbert, Silvia; García-Rojas, Jorge; Rodríguez, Mónica
Publication:
The Astrophysical Journal Supplement Series, Volume 120, Issue 1, pp. 113-129. (ApJS Homepage)
Publication Date:
01/1999
Origin:
APJ
ApJ Keywords:
ISM: H II REGIONS, ISM: ABUNDANCES, ISM: INDIVIDUAL: MESSIER NUMBER: M8, LINE: IDENTIFICATION
DOI:
10.1086/313172
Bibliographic Code:
1999ApJS..120..113E

Abstract

We present echelle spectroscopy in the 3500-10300 Å range of the Hourglass Nebula, which is embedded in the Galactic H II region M8. The data were obtained using the 2.1 m telescope at Observatorio Astronómico Nacional in San Pedro Mártir, Baja California. We have measured the intensities of 274 emission lines, in particular 88 permitted lines of C^+, N^0, N^+, O^0, O^+, Ne^0, S^0, S^+, Si^0, Si^+, and Si^++, some of them produced by recombination only and others mainly by fluorescence. We have determined electron temperatures and densities using different line intensity ratios. We derive the He^+, C^++, O^+, and O^++ ionic abundances as well as-for the first time in a nebular object-the total O abundance from recombination lines; these nebular values are independent of the temperature structure of the nebula. We have also derived abundances from collisionally excited lines for a large number of ions and elements; these abundances do depend on the temperature structure. Accurate t^2 values have been derived by comparing the C^++, O^+, and O^++ ionic abundances obtained making use of both collisionally excited lines and recombination lines. A comparison of the solar, Orion Nebula, and M8 chemical abundances is made.

Associated Articles

Source Paper     Catalog Description    

Bibtex entry for this abstract   Preferred format for this abstract (see Preferences)
   

Find Similar Abstracts:

Use: Authors
Title
Keywords (in text query field)
Abstract Text
Return: Query Results Return    items starting with number
Query Form
Database: Astronomy
Physics
arXiv e-prints