The infrared emission bands. II. A spatial and spectral study of the Orion bar

Journal Article · Fri Sep 01 04:00:00 EDT 1989 · Astrophysical Journal; (USA)

DOI:https://doi.org/10.1086/167844· OSTI ID:5288265

Bregman, J D; Allamandola, L J; Witteborn, F C; Tielens, A G.G.M.; Geballe, T R ^[1]

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1. NASA, Ames Research Center, Moffett Field, CA (USA)

The 3-13 micron emission of the Orion Bar is spectroscopically and spatially studied. There are three emission components, one from 'classical' dust that accounts for the bulk of the emission longward of 20 microns, a second one from large amorphous carbon grains or polycyclic aromatic hydrocarbon (PAH) clusters accounting for the broad features, and a third from PAH molecules that accounts for the sharp bands. The 3.3 and 11.3 micron features, which are due to C-H modes, are well correlated spatially, while the 7.7 micron band, due to C=C modes, has a different distribution than the 3.3 and 11.1 micron bands. It is concluded that the sharp emission bands arise in the photodissociation transition region between the H II region and the molecular cloud and are not present in the H II region. The broad continuum feature from 11-13 microns is strong in both regions. 30 refs.

• OSTI ID: 5288265
• Journal Information: Astrophysical Journal; (USA), Journal Name: Astrophysical Journal; (USA) Vol. 344; ISSN ASJOA; ISSN 0004-637X
• Country of Publication: United States
• Language: English

Related Subjects

640105* -- Astrophysics & Cosmology-- Galaxies
71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
CARBON
COSMIC GASES
COSMIC RADIO SOURCES
DISTRIBUTION
ELEMENTS
EMISSION SPECTRA
FLUIDS
GASES
H2 REGIONS
HYDROCARBONS
INFRARED SPECTRA
INTERSTELLAR GRAINS
INTERSTELLAR SPACE
MATHEMATICAL MODELS
NONMETALS
ORGANIC COMPOUNDS
PARTICLES
SPACE
SPATIAL DISTRIBUTION
SPECTRA