A multicomponent model of the infrared emission from Comet Halley

Krishna Swamy, K. S. ; Sandford, Scott A. ; Allamandola, Louis J. ; Witteborn, Fred C. ; Bregman, Jesse D. (1988) A multicomponent model of the infrared emission from Comet Halley ICARUS, 75 (2). pp. 351-370. ISSN 0019-1035

Full text not available from this repository.

Official URL: http://linkinghub.elsevier.com/retrieve/pii/001910...

Related URL: http://dx.doi.org/10.1016/0019-1035(88)90009-7

Abstract

We have attempted to incorporate the compositional information available from interplanetary dust particles (IDPs) and the recent Halley flybys into a coherent model to account for cometary infrared emission. We show that the entire infrared emission spectrum of Comet Halley is consistent with the presence of three general dust particle types. These dust types are (i) amorphous carbon grains, (ii) crystalline silicate grains, and (iii) crystalline silicate grains with thin carbonaceous coatings. In analogy with IDPs, the thin carbonaceous coatings on the silicate minerals may be responsible for the dark appearance of most comets. Good fits to the observational data are found for particle populations having particle size distributions similar to those inferred for Comet Halley, and silicate to amorphous carbon mass ratios of 8 to 40, values consistent with IDP and flyby data. Composite particles in which all the carbon resides in thick mantles on silicate cores fail to simultaneously match both the spectral and compositional constraints. Finally, the apparent strength of the 10-μm silicate feature is found to be particle size dependent. Consequently, as has been noted before, the absence of an obvious 10-μm feature in other comets does not imply the absence of silicates, but may instead imply the dominance of large silicate grains.

Item Type:Article
Source:Copyright of this article belongs to Elsevier Science.
ID Code:18208
Deposited On:17 Nov 2010 12:59
Last Modified:04 Jun 2011 09:41

Repository Staff Only: item control page