Ions in grain mantles - A new explanation for the 6. 86 micron absorption in W33A

Journal Article · Thu Jun 01 04:00:00 EDT 1989 · Astrophysical Journal; (USA)

DOI:https://doi.org/10.1086/185464· OSTI ID:5643673

Grim, R J.A.; Greenberg, J M; Schutte, W A; Schmitt, B ^[1]

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

The 6.86-micron absorption in W33A has been investigated using the results of laboratory experiments simulating the photochemistry of interstellar grain mantles. The 5-8-micron IR spectrum, and particularly the 6.86-micron absorption, of W33A can be reproduced with ultraviolet irradiated water-rich ices. The 5-8-micron spectrum of W33A exhibits effects which are interpreted as due to dust material heated to different temperatures along the line of sight. Photolyzed dust mantles with a temperature less than 100 K provide the 6.0-micron absorption, while dust mantles heated to more than 100 K are the main contributors to the 6.86-micron absorption feature. Different photolysis and heating scenarios, as well as line of sight effects, are required to account for the 5-8-micron spectra of other protostellar objects. 20 refs.

• OSTI ID: 5643673
• Journal Information: Astrophysical Journal; (USA), Journal Name: Astrophysical Journal; (USA) Vol. 341; ISSN ASJOA; ISSN 0004-637X
• Country of Publication: United States
• Language: English

Related Subjects

640102* -- Astrophysics & Cosmology-- Stars & Quasi-Stellar
Radio & X-Ray Sources
71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
ABSORPTION SPECTRA
CHARGED PARTICLES
CHEMICAL REACTIONS
CHEMISTRY
COSMIC DUST
COSMOCHEMISTRY
DECOMPOSITION
DUSTS
ICE
INFRARED SPECTRA
INTERSTELLAR GRAINS
IONS
MOLECULAR IONS
PARTICLES
PHOTOCHEMICAL REACTIONS
PHOTOLYSIS
PROTOSTARS
SPECTRA