Spectroscopy of the 3. 4 micron emission feature in comet Halley

Journal Article · Mon Dec 01 04:00:00 EST 1986 · Astrophys. J.; (United States)

DOI:https://doi.org/10.1086/184806· OSTI ID:6446220

Baas, F; Geballe, T R; Walther, D M

Infrared spectra in the 3-5 micron region have been obtained of Comet Halley after perihelion, at heliocentric distances of 1.6 and 2.0 AU. A broad emission feature, peaking near 3.4 microns and containing some spectral substructure, was observed, while at longer wavelengths only a featureless blackbody emission spectrum was seen. The emission feature probably arises from UV-pumped infrared fluorescence of organic molecules which are either in the gas phase or are embedded in very small grains. In the former interpretation the molecules must be quite large. These results lend support to the idea that comets formed out of interstellar grains whose molecular ice mantles largely consist of nonvolatile complex organic molecules. 21 references.

• Research Organization: U.K. Infrared Telescope, Hilo, HI; Leiden Rijksuniversiteit, Netherlands; Stichting Astronomisch Onderzoek in Nederland, Amsterdam, Netherlands
• OSTI ID: 6446220
• Journal Information: Astrophys. J.; (United States), Journal Name: Astrophys. J.; (United States) Vol. 311; ISSN ASJOA
• Country of Publication: United States
• Language: English

Related Subjects

640107* -- Astrophysics & Cosmology-- Planetary Phenomena
71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
BLACKBODY RADIATION
COMETS
ELECTROMAGNETIC RADIATION
EMISSION SPECTRA
ENERGY SPECTRA
HALLEY COMET
INFRARED SPECTRA
INTERSTELLAR GRAINS
ORGANIC COMPOUNDS
ORIGIN
PARTICLES
RADIATIONS
SPECTRA