The excitation of 12 micron emission from very small particles. [Star-illuminated reflection nebulae]

Journal Article · Wed Aug 01 04:00:00 EDT 1990 · Astrophysical Journal; (USA)

DOI:https://doi.org/10.1086/169072· OSTI ID:6405856

Sellgren, K; Luan, L; Werner, M W ^[1]

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1. Hawaii Univ., Honolulu (USA) California Univ., Berkeley (USA) NASA, Ames Research Center, Moffett Field, CA (USA)

The results of IRAS observations of visual reflection nebulae illuminated by stars with effective temperatures between 3000 and 33,000 K are presented. The ratio of the energy radiated in the IRAS 12-microns band to the total energy radiated at far-infrared wavelengths (60 and 100 microns) is about 0.2, with little or no dependence on the temperature of the illuminating star for stellar temperatures between about 5000 and 33,000 K. This is interpreted as requiring that visual photons as well as ultraviolet photons are capable of exciting 12-microns emission from very small particles. 39 refs.

• OSTI ID: 6405856
• Journal Information: Astrophysical Journal; (USA), Journal Name: Astrophysical Journal; (USA) Vol. 359; 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
BRIGHTNESS
COSMIC DUST
DUSTS
ELECTROMAGNETIC RADIATION
ELEMENTARY PARTICLES
EMISSION SPECTRA
ENERGY-LEVEL TRANSITIONS
EXCITATION
INFRARED RADIATION
INTERSTELLAR SPACE
MASSLESS PARTICLES
NEBULAE
OPTICAL PROPERTIES
PHOTONS
PHYSICAL PROPERTIES
RADIATIONS
SPACE
SPECTRA
STELLAR RADIATION