Far-infrared properties of NGC 6822

Journal Article · Sun Mar 31 23:00:00 EST 1991 · Astrophysical Journal; (United States)

DOI:https://doi.org/10.1086/169878· OSTI ID:5540786

Gallagher, III, J S; Hunter, D A; Gillett, F C; Rice, W L ^[1]

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1. AURA, Inc., Washington, DC (USA) Lowell Observatory, Flagstaff, AZ (USA) National Optical Astronomy Observatories, Tucson, AZ (USA) JPL, Pasadena, CA (USA)

IRAS FIR maps of NGC 6822, one of the few noninteracting Magellanic irregular galaxies resolved in the FIR by IRAS, are examined and compared to optical and H I data. The diffuse FIR emission at large radii from the center of the galaxy is found to be due to Galactic cirrus. There is a general correspondence between H-alpha and FIR emission in that FIR peaks are associated with major H II complexes, but the ratio of the FIR to the H-alpha emission varies between these complexes by about a factor of five. H I mass-to-FIR luminosity ratios cover a similar range for the three major H I cloud complexes in NGC 6822. More than about half of the FIR flux is produced in regions near H II region complexes. The remaining flux comes from diffuse FIR emission that extends over the entire optically visible galaxy. A model for the galaxy is discussed in which the galaxy is fairly transparent and the FIR is strongest where there is a strong UV source and higher optical depth due to dust in gas clouds. 43 refs.

• OSTI ID: 5540786
• Journal Information: Astrophysical Journal; (United States), Journal Name: Astrophysical Journal; (United States) Vol. 371; 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
COMPARATIVE EVALUATIONS
COSMIC RADIO SOURCES
ELECTROMAGNETIC RADIATION
EMISSION SPECTRA
FAR INFRARED RADIATION
GALAXIES
H1 REGIONS
H2 REGIONS
INFRARED RADIATION
MAGELLANIC CLOUDS
MASS
MATHEMATICAL MODELS
RADIATIONS
SPECTRA
STAR EVOLUTION
VISIBLE RADIATION