The Sagittarius B2 molecular cloud: An extreme case of a galactic center giant molecular cloud

Thesis/Dissertation · Sun Jan 01 04:00:00 EST 1989

OSTI ID:7059763

Lis, D C

A model was developed of the Sagittarius B2 molecular cloud based on the J = 1 yields 0 and 2 yields 1 transitions of (13)CO and C(18)O, as well as on the far infrared and submillimeter continuum emission from the dust, in order to determine the physical conditions in this source. The total mass of the cloud is dominated by an envelope which consists of a constant density component and a power law component with a radial exponent of -2. The virial mass of the cloud is a factor of approx. 2 higher than the molecular mass, suggesting that Sgr B2 is close to virial equilibrium. The Sgr B2(M) and (N) continuum sources are situated inside small dense cores embedded in the extended clouds. The middle source is much more luminous than the northern source. The observed change in the middle-to-north peak flux ratio between 350 mu and 1300 mu is primarily a result of the difference in luminosity. In order to compare Sgr B2 with other Galactic Center clouds, the J = 1 yields 0 transition of (13)CO was observed in two selected Galactic Center fields centered on the G1.1 to 0.1 and G359.4 to 0.1 continuum sources. The molecular clouds observed there seem to be distinctively different from Sgr B2.

• Research Organization: Massachusetts Univ., Amherst, MA (USA)
• OSTI ID: 7059763
• Country of Publication: United States
• Language: English

Related Subjects

640105* -- Astrophysics & Cosmology-- Galaxies
71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
ATMOSPHERES
CLOUDS
COSMIC DUST
DATA
DUSTS
ELECTROMAGNETIC RADIATION
EXPERIMENTAL DATA
FAR INFRARED RADIATION
GALAXY NUCLEI
INFORMATION
INFRARED RADIATION
LUMINOSITY
MASS
MATHEMATICAL MODELS
MICROWAVE RADIATION
NUMERICAL DATA
OPTICAL PROPERTIES
PHYSICAL PROPERTIES
RADIATION SOURCES
RADIATIONS
STAR MODELS
STARS
STELLAR ATMOSPHERES