Observations of the 63 micron (O I) emission line in the Orion and Omega Nebulae

Journal Article · Mon Jan 01 04:00:00 EST 1979 · Astrophys. J., Lett.; (United States)

DOI:https://doi.org/10.1086/182861· OSTI ID:6198827

Melnick, G; Gull, G E; Harwit, M

We report the first observations of the 63 ..mu..m fine-structure transition rho/sup 4/: /sup 3/P/sub 1/..-->../sup 3/P/sub 2/ for neutral atomic oxygen. The measurements were obtained during a series of flights on the NASA Lear Jet at an altitude of approx.13.7 km. In the Orion Nebula (M42) our observed line strength is 8 x 10/sup -5/ W cm/sup -2/, which we estimate to be approx.0.3% of the energy radiated at all wavelengths. For the Omega Nebula (M17) the line strength is 2.4 x 10/sup -15/ W cm/sup -2/, and the fraction of the total radiated power is slightly higher. These figures refer to a 4' x 6' field of view centered on the peak far-infrared emission from each source. The uncertainty in the line strength is approx.50% and is caused by variable water-vapor absorption along the flight path of the airplane. Our estimate of the line position is 63.2 ..mu..m (+0.1, -0.2 ..mu..m). The prime uncertainty is due to the uncertain position of the (O I) emitting regions in our field of view.

• Research Organization: Center for Radiophysics and Space Research, Cornell University
• OSTI ID: 6198827
• Journal Information: Astrophys. J., Lett.; (United States), Journal Name: Astrophys. J., Lett.; (United States) Vol. 227:1; ISSN AJLEA
• Country of Publication: United States
• Language: English

Related Subjects

640105* -- Astrophysics & Cosmology-- Galaxies
71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
CHEMICAL COMPOSITION
CHEMISTRY
COSMIC GASES
COSMOCHEMISTRY
CRYOGENIC FLUIDS
ELEMENTS
EMISSION SPECTRA
ENERGY LEVELS
ENERGY-LEVEL TRANSITIONS
EXCITATION
FINE STRUCTURE
FLUIDS
GASES
INFRARED SPECTRA
NEBULAE
NONMETALS
OXYGEN
SPECTRA