Ultracold molecular gas toward the galactic center

Journal Article · Fri Feb 01 04:00:00 EST 1980 · Astrophys. J.; (United States)

DOI:https://doi.org/10.1086/157686· OSTI ID:5295247

Zuckerman, B; Kuiper, T B.H.

We observed several positions near the galactic center (Sgr A) in the J=1..-->..0 rotational transitions of /sup 12/Co, /sup 13/Co, and C/sup 18/O to better understand the nature of the ''very cold'' molecular gas whose existence was first stressed by Liszt and his colleagues. We established that several dips in the /sup 12/CO spectra are due to optically thick clouds of foreground CO with relatively low excitation temperatures (T/sub ex/). We find T/sub ex/> or approx. =5.3 K for all such /sup 12/CO clouds in all five of the directions that we observed. Such clouds fall at the extreme low end of the measured range of T/sub ex/ for nearby dark clouds, but would, nonetheless, generally be detected in sensitive emission surveys of galactic Co.

• Research Organization: University of Maryland
• OSTI ID: 5295247
• Journal Information: Astrophys. J.; (United States), Journal Name: Astrophys. J.; (United States) Vol. 235:3; ISSN ASJOA
• Country of Publication: United States
• Language: English

Related Subjects

640105* -- Astrophysics & Cosmology-- Galaxies
71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
CARBON COMPOUNDS
CARBON MONOXIDE
CARBON OXIDES
CHALCOGENIDES
CHEMISTRY
COSMIC GASES
COSMIC RADIATION
COSMOCHEMISTRY
ELECTROMAGNETIC RADIATION
FLUIDS
GALAXIES
GALAXY NUCLEI
GASES
INFRARED RADIATION
INTERSTELLAR SPACE
IONIZING RADIATIONS
MILKY WAY
MOLECULES
NEBULAE
OXIDES
OXYGEN COMPOUNDS
RADIATIONS
SPACE