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Title: OI and OIII in Sgr A: neutral and ionized gas at the Galactic center

Abstract

We have mapped the /sup 3/P/sub 1/-/sup 3/P/sub 2/ fine structure line emission at 63 microns from neutral oxygen in the vicinity of the galactic center. The emission is extended over more than 4' and is centered on Sgr A West. We conclude that the bulk of the OI emission arises in a predominantly neutral region outside of the ionized central 3 pc of our galaxy. Assuming that the oxygen is collisionally excited by neutral hydrogen impact, we estimate that the gas temperatures in this region are >130K, that is, significantly higher than the dust temperature of 70K. The OI line center velocities change systematically along the galactic plane in a manner consistent with galactic rotation. However, the unusual velocity distribution and linewidths suggest that the motions have a large noncircular component and that there are large scale inhomogeneities in the OI-emitting gas. We also have detected the 88 micron /sup 3/P/sub 1/-/sup 3/P/sub 0/ fine structure line of OIII in a 45triangle-solid FWHM beam centered on Sgr A West. The ratio of this line intensity to that of 52 micron /sup 3/P/sub 2/-/sup 3/P/sub 1/ line indicates that most of the ionized gas in this region has electron densitymore » >10/sup 4/ cm/sup -3/.« less

Authors:
; ; ; ; ; ;
Publication Date:
Research Org.:
University of California, Berkeley, CA
OSTI Identifier:
5289966
Report Number(s):
CONF-820139-
Journal ID: CODEN: APCPC; TRN: 82-016654
Resource Type:
Journal Article
Journal Name:
AIP Conf. Proc.; (United States)
Additional Journal Information:
Journal Volume: 83:1; Conference: Workshop on the galactic center, Pasadena, CA, USA, 7 Jan 1982
Country of Publication:
United States
Language:
English
Subject:
71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSICS; GALAXY NUCLEI; EMISSION SPECTRA; FAR INFRARED RADIATION; INFRARED SPECTRA; IONIZED GASES; MILKY WAY; OXYGEN; OXYGEN IONS; FABRY-PEROT INTERFEROMETER; CHARGED PARTICLES; ELECTROMAGNETIC RADIATION; ELEMENTS; FLUIDS; GALAXIES; GASES; INFRARED RADIATION; INTERFEROMETERS; IONS; MEASURING INSTRUMENTS; NONMETALS; RADIATIONS; SPECTRA; 640105* - Astrophysics & Cosmology- Galaxies

Citation Formats

Genzel, R, Watson, D, Townes, C, Lester, D, Dinerstein, H, Werner, M, and Storey, J. OI and OIII in Sgr A: neutral and ionized gas at the Galactic center. United States: N. p., 1982. Web. doi:10.1063/1.33504.
Genzel, R, Watson, D, Townes, C, Lester, D, Dinerstein, H, Werner, M, & Storey, J. OI and OIII in Sgr A: neutral and ionized gas at the Galactic center. United States. https://doi.org/10.1063/1.33504
Genzel, R, Watson, D, Townes, C, Lester, D, Dinerstein, H, Werner, M, and Storey, J. 1982. "OI and OIII in Sgr A: neutral and ionized gas at the Galactic center". United States. https://doi.org/10.1063/1.33504.
@article{osti_5289966,
title = {OI and OIII in Sgr A: neutral and ionized gas at the Galactic center},
author = {Genzel, R and Watson, D and Townes, C and Lester, D and Dinerstein, H and Werner, M and Storey, J},
abstractNote = {We have mapped the /sup 3/P/sub 1/-/sup 3/P/sub 2/ fine structure line emission at 63 microns from neutral oxygen in the vicinity of the galactic center. The emission is extended over more than 4' and is centered on Sgr A West. We conclude that the bulk of the OI emission arises in a predominantly neutral region outside of the ionized central 3 pc of our galaxy. Assuming that the oxygen is collisionally excited by neutral hydrogen impact, we estimate that the gas temperatures in this region are >130K, that is, significantly higher than the dust temperature of 70K. The OI line center velocities change systematically along the galactic plane in a manner consistent with galactic rotation. However, the unusual velocity distribution and linewidths suggest that the motions have a large noncircular component and that there are large scale inhomogeneities in the OI-emitting gas. We also have detected the 88 micron /sup 3/P/sub 1/-/sup 3/P/sub 0/ fine structure line of OIII in a 45triangle-solid FWHM beam centered on Sgr A West. The ratio of this line intensity to that of 52 micron /sup 3/P/sub 2/-/sup 3/P/sub 1/ line indicates that most of the ionized gas in this region has electron density >10/sup 4/ cm/sup -3/.},
doi = {10.1063/1.33504},
url = {https://www.osti.gov/biblio/5289966}, journal = {AIP Conf. Proc.; (United States)},
number = ,
volume = 83:1,
place = {United States},
year = {Sat May 01 00:00:00 EDT 1982},
month = {Sat May 01 00:00:00 EDT 1982}
}