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A two component model for thermal emission from organic grains in comet halley
| Content Provider | NASA Technical Reports Server (NTRS) |
|---|---|
| Author | Sagan, Carl Chyba, Christopher |
| Copyright Year | 1988 |
| Description | Observations of Comet Halley in the near infrared reveal a triple-peaked emission feature near 3.4 micrometer, characteristic of C-H stretching in hydrocarbons. A variety of plausible cometary materials exhibit these features, including the organic residue of irradiated candidate cometary ices (such as the residue of irradiated methane ice clathrate, and polycyclic aromatic hydrocarbons. Indeed, any molecule containing -CH3 and -CH2 alkanes will emit at 3.4 micrometer under suitable conditions. Therefore tentative identifications must rest on additional evidence, including a plausible account of the origins of the organic material, a plausible model for the infrared emission of this material, and a demonstration that this conjunction of material and model not only matches the 3 to 4 micrometer spectrum, but also does not yield additional emission features where none is observed. In the case of the residue of irradiated low occupancy methane ice clathrate, it is argued that the lab synthesis of the organic residue well simulates the radiation processing experienced by Comet Halley. |
| File Size | 105264 |
| Page Count | 2 |
| File Format | |
| Alternate Webpage(s) | http://archive.org/details/NASA_NTRS_Archive_19890003969 |
| Archival Resource Key | ark:/13960/t01z93c7q |
| Language | English |
| Publisher Date | 1988-09-01 |
| Access Restriction | Open |
| Subject Keyword | Astronomy Cometary Atmospheres Thermal Emission Cosmic Dust Organic Materials Polycyclic Aromatic Hydrocarbons Emission Spectra Spectrum Analysis Hydrocarbons Ice Infrared Spectra Halley's Comet Ntrs Nasa Technical Reports Server (ntrs) Nasa Technical Reports Server Aerodynamics Aircraft Aerospace Engineering Aerospace Aeronautic Space Science |
| Content Type | Text |
| Resource Type | Article |
