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Size and density distribution of very small dust grains in the Barnard 5 cloudThe effects of the temperature fluctuations in small graphite grains on the energy spectrum and the IR surface brightness of an isolated dust cloud heated externally by the interstellar radiation field were investigated using a series of models based on a radiation transport computer code. This code treats self-consistently the thermal coupling between the transient heating of very small dust grains and the equilibrium heating of conventional large grains. The model results were compared with the IRAS observations of the Barnard 5 (B5) cloud, showing that the 25-micron emission of the cloud must be produced by small grains with a 6-10 A radius, which also contribute about 50 percent to the observed 12-micron emission. The remaining 12 micron flux may be produced by the polycyclic aromatic hydrocarbons. The 60-and 100-micron radiation is dominated by emission from large grains heated under equilibrium conditions.
Document ID
19910050451
Document Type
Reprint (Version printed in journal)
External Source(s)
Authors
Lis, Dariusz C.
(California Institute of Technology Pasadena, United States)
Leung, Chun Ming
(Rensselaer Polytechnic Institute, Troy, NY, United States)
Date Acquired
August 15, 2013
Publication Date
May 10, 1991
Publication Information
Publication: Astrophysical Journal, Part 2 - Letters
Volume: 372
ISSN: 0004-637X
Subject Category
Astrophysics
Funding Number(s)
CONTRACT_GRANT: NAG5-1182
CONTRACT_GRANT: AF-AFOSR-89-104
CONTRACT_GRANT: NSF AST-88-14405
Distribution Limits
Public
Copyright
Other
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