Chlorine in dense interstellar clouds - the abundance of HCl in OMC-1

Journal Article · Thu Aug 01 00:00:00 EDT 1985 · Astrophys. J.; (United States)

DOI:https://doi.org/10.1086/163394· OSTI ID:5799231

Blake, G A; Keene, J; Phillips, T G

The first detection of a chlorine-bearing molecular species in the interstellar medium via emission from the J = 1-0 transition of HCl at 625.9 GHz toward OMC-1 is reported. The relative strengths, widths, and velocities of the resolved hyperfine components are consistent with moderate optical depth emission originating from dense, quiescent molecular cloud material. The overall emission strength implies a fractional abundance of f(HCl/H2) of about (0.5-5.0) x 10 to the -8th, depending on the density of the emitting region. This is approximately an order of magnitude below previous theoretical estimates and a factor of 3-30 below the cosmic abundance of Cl. Recent laboratory work suggests that the lowered fractional abundance of HCl is caused by a combination of depletion onto grains with gas-phase loss processes such as the reaction of HCl with C(+). 40 references.

• Research Organization: California Institute of Technology (CalTech), Pasadena, CA (United States)
• OSTI ID: 5799231
• Journal Information: Astrophys. J.; (United States), Vol. 295
• Country of Publication: United States
• Language: English

Related Subjects

71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
HYDROCHLORIC ACID
ABUNDANCE
INTERSTELLAR SPACE
CHEMICAL COMPOSITION
CHLORINE
COSMIC GASES
COSMOCHEMISTRY
EMISSION SPECTRA
MOLECULES
SPECTROSCOPY
CHEMISTRY
ELEMENTS
FLUIDS
GASES
HALOGENS
HYDROGEN COMPOUNDS
INORGANIC ACIDS
NONMETALS
SPACE
SPECTRA
640105* - Astrophysics & Cosmology- Galaxies