Millimeter-wave absorption features toward the galactic center: evidence for a massive nuclear disk
Journal Article
·
· Astrophys. J.; (United States)
We report the detection of molecular gas which appears in absorption at large negative velocities near the galaxtic center for a number of millimeter-wavelength molecular transitions previously observed only in emisson. We have made millimeter-continuum emission measurements which show that the absorbing line is optically thick in HCO/sup +/ and has an excitation temperature consistent with no collisional excitation form --117 to --83 km s/sup -1/ toward Sgr B2. At these velocities CO is seen in emission at a level of 3 K. We obtain molecular column densities for five species and estimate a molecular hydrogen column density of approx.5 x 10/sup 23/ cm/sup -2/ to Sgr B2. We associate this absorbing gas with the nuclear disk and esimate that the total mass involved is approx.8 x 10/sup 9/ M/sub sun/. It is shown that spiral arms in the galactic disk also appear as absorption features in HCO/sup +/ and HCN.
- Research Organization:
- Bell Laboratories, Crawford Hill Laboratory
- OSTI ID:
- 6535726
- Journal Information:
- Astrophys. J.; (United States), Journal Name: Astrophys. J.; (United States) Vol. 243:1; ISSN ASJOA
- Country of Publication:
- United States
- Language:
- English
Similar Records
HCO/sup +/emission in the galactic center region. I. observations
SUBMILLIMETER ARRAY/PLATEAU DE BURE INTERFEROMETER MULTIPLE LINE OBSERVATIONS OF THE NEARBY SEYFERT 2 GALAXY NGC 1068: SHOCK-RELATED GAS KINEMATICS AND HEATING IN THE CENTRAL 100 pc?
The excitation of HCN and HCO{sup +} in the galactic center circumnuclear disk
Journal Article
·
Wed Oct 01 00:00:00 EDT 1980
· Astrophys. J.; (United States)
·
OSTI ID:6918667
SUBMILLIMETER ARRAY/PLATEAU DE BURE INTERFEROMETER MULTIPLE LINE OBSERVATIONS OF THE NEARBY SEYFERT 2 GALAXY NGC 1068: SHOCK-RELATED GAS KINEMATICS AND HEATING IN THE CENTRAL 100 pc?
Journal Article
·
Wed Jul 20 00:00:00 EDT 2011
· Astrophysical Journal
·
OSTI ID:21578337
The excitation of HCN and HCO{sup +} in the galactic center circumnuclear disk
Journal Article
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Mon Dec 09 23:00:00 EST 2013
· Astrophysical Journal
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OSTI ID:22348517
Related Subjects
640105* -- Astrophysics & Cosmology-- Galaxies
71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
ABSORPTION SPECTRA
CARBON COMPOUNDS
CARBON MONOXIDE
CARBON OXIDES
CHALCOGENIDES
COSMIC GASES
CYANIDES
ENERGY-LEVEL TRANSITIONS
FLUIDS
FUNCTIONS
GALAXIES
GALAXY NUCLEI
GASES
HYDROCARBONS
HYDROCYANIC ACID
HYDROGEN COMPOUNDS
INORGANIC ACIDS
MILKY WAY
NITRILES
ORGANIC COMPOUNDS
ORGANIC NITROGEN COMPOUNDS
OXIDES
OXYGEN COMPOUNDS
PROPIOLONITRILE
SPECTRA
SPECTRAL DENSITY
SPECTRAL FUNCTIONS
71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
ABSORPTION SPECTRA
CARBON COMPOUNDS
CARBON MONOXIDE
CARBON OXIDES
CHALCOGENIDES
COSMIC GASES
CYANIDES
ENERGY-LEVEL TRANSITIONS
FLUIDS
FUNCTIONS
GALAXIES
GALAXY NUCLEI
GASES
HYDROCARBONS
HYDROCYANIC ACID
HYDROGEN COMPOUNDS
INORGANIC ACIDS
MILKY WAY
NITRILES
ORGANIC COMPOUNDS
ORGANIC NITROGEN COMPOUNDS
OXIDES
OXYGEN COMPOUNDS
PROPIOLONITRILE
SPECTRA
SPECTRAL DENSITY
SPECTRAL FUNCTIONS