Submillimeter observations of NGC 2024, OMC-2, and MON R-2

Journal Article · Sat May 15 04:00:00 EDT 1976 · Astrophys. J.; (United States)

DOI:https://doi.org/10.1086/154359· OSTI ID:7344897

Hudson, H S; Soifer, B T

We report new submillimeter (effective wavelength approx.400 ..mu..) observations of three dense molecular clouds: NGC 2024 (Orion B) OMC-2 (in Orion A) and Mon R-2. These objects strongly resemble the far-infrared source in the Kleinmann-Low nebula in Orion A. An extensive map of NGC 2024 shows the peak of submillimeter brightness to coincide with the peak locations of far-infrared (approx.100 ..mu..) continuum and HCN molecular-line emissions. The submillimeter and far-infrared brightness distributions differ in spatial detail, suggesting that the submillimeter emission comes from a cool region with temperature approx.25 K (inferred from the surface brightness of the optically thick /sup 12/C/sup 16/O line). Arguments based upon the column density derived from optically thin molecular lines yield an effective mass-absorption coefficient of 17 cm/sup 2/ gm/sup -1/ for the continuum opacity at 400 ..mu..; however, this estimate is subject to large uncertainties.We suggest that the star 2024 No. 2 is imbedded in the molecular cloud and supplies the energy of the submillimeter emission. (AIP)

• Research Organization: Department of Physics, University of California, San Diego
• OSTI ID: 7344897
• Journal Information: Astrophys. J.; (United States), Journal Name: Astrophys. J.; (United States) Vol. 206:1; ISSN ASJOA
• Country of Publication: United States
• Language: English

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71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
COSMIC DUST
COSMIC RADIO SOURCES
DUSTS
ELECTROMAGNETIC RADIATION
INFRARED RADIATION
INTERSTELLAR SPACE
LUMINOSITY
MOLECULES
NEBULAE
OPTICAL PROPERTIES
OXYGEN COMPOUNDS
PHYSICAL PROPERTIES
RADIATIONS
RADIOWAVE RADIATION
SILICATES
SILICON COMPOUNDS
SPACE