OI and OIII in Sgr A: neutral and ionized gas at the Galactic center
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/.
- Research Organization:
- University of California, Berkeley, CA
- OSTI ID:
- 5289966
- Report Number(s):
- CONF-820139-; TRN: 82-016654
- Journal Information:
- AIP Conf. Proc.; (United States), Vol. 83:1; Conference: Workshop on the galactic center, Pasadena, CA, USA, 7 Jan 1982
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
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