CO 7. -->. 6 submillimeter emission from the Galactic center: Warm molecular gas and the rotation curve in the central 10 parsecs

Journal Article · Mon Jul 15 04:00:00 EDT 1985 · Astrophys. J., Lett. Ed.; (United States)

DOI:https://doi.org/10.1086/184516· OSTI ID:5265985

Harris, A I; Jaffe, D T; Silber, M; Genzel, R

We have mapped bright CO J = 7 ..-->.. 6 submillimeter line emission in the central; 10 pc of the Galaxy. This is the first detection of the 7 ..-->.. 6 line from the Galactic center, made with a newly constructed submillimeter heterodyne spectrometer. The 372 ..mu..m CO emission comes from a dense, clumpy disk (n/sub H/roughly-equal3 x 10/sup 4/ cm/sup -3/, mass roughly-equal10/sup 4/ M/sub sun/) of temperature approx.300 K. The luminosity of all CO rotational lines emitted from this approx.4' diameter region is about 2 x 10/sup 4/ L/sub sun/. CO line emission is a major contribution to the cooling of the interstellar gas near Sgr A. Mass outflow from the center or cloud-cloud collisions may cause shocks which heat the warm molecular gas. The kinetic energy dissipation rate in shocks necessary is > or =2 x 10/sup 5/ L/sub sun/. This requires a very large mass-loss rate (> or approx. =0.5 M/sub sun/ yr/sup -1/) or efficient regenerationn of cloud-cloud turbulence throughout the region on a very short time scale (< or =5 x 10/sup 3/ yr). Alternatively, UV radiation from the Galactic center could heat the molecular gas if CO self-shielding is effective. The CO abundance must then be approx.10/sup -4/ in the ''photodissociation'' region (A/sub v/< or =5), where most of the UV energy is absorbed.

• Research Organization: Space Sciences Laboratory and Department of Physics, University of California, Berkeley
• OSTI ID: 5265985
• Journal Information: Astrophys. J., Lett. Ed.; (United States), Journal Name: Astrophys. J., Lett. Ed.; (United States) Vol. 294:2; ISSN AJLEA
• Country of Publication: United States
• Language: English

Related Subjects

640105* -- Astrophysics &amp; Cosmology-- Galaxies
71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
CARBON COMPOUNDS
CARBON MONOXIDE
CARBON OXIDES
CHALCOGENIDES
COSMIC DUST
COSMIC GASES
DISTRIBUTION
DUSTS
ELECTROMAGNETIC RADIATION
FLUIDS
GALAXIES
GALAXY NUCLEI
GASES
INFRARED RADIATION
INTERSTELLAR SPACE
MASS DISTRIBUTION
MILKY WAY
MOLECULES
MOTION
OXIDES
OXYGEN COMPOUNDS
RADIATIONS
ROTATION
SPACE
SPATIAL DISTRIBUTION