Size and density distribution of very small dust grains in the Barnard 5 cloud

Journal Article · Wed May 01 04:00:00 EDT 1991 · Astrophysical Journal; (United States)

DOI:https://doi.org/10.1086/186035· OSTI ID:5503369

Lis, D C; Leung, C Ming ^[1]

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1. California Institute of Technology, Pasadena (USA) Rensselaer Polytechnic Institute, Troy, NY (USA)

The 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. 21 refs.

• OSTI ID: 5503369
• Journal Information: Astrophysical Journal; (United States), Journal Name: Astrophysical Journal; (United States) Vol. 372; 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
AROMATICS
BRIGHTNESS
COMPARATIVE EVALUATIONS
COSMIC DUST
COSMIC GASES
CRYSTAL STRUCTURE
DUSTS
ELECTROMAGNETIC RADIATION
ENERGY SPECTRA
FLUIDS
GASES
GRAIN SIZE
HEATING
HYDROCARBONS
INFRARED RADIATION
INTERSTELLAR GRAINS
INTERSTELLAR SPACE
MATHEMATICAL MODELS
MICROSTRUCTURE
NEBULAE
OPACITY
OPTICAL PROPERTIES
ORGANIC COMPOUNDS
PARTICLES
PHYSICAL PROPERTIES
POLYCYCLIC AROMATIC HYDROCARBONS
RADIATION TRANSPORT
RADIATIONS
SIZE
SPACE
SPECTRA
TEMPERATURE GRADIENTS