Infrared Spectra of Meteoritic SiC Grains

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dc.creatorAndersen, A. C.
dc.creatorJager, C.
dc.creatorMutschke, H.
dc.creatorBraatz, A.
dc.creatorClement, C.
dc.creatorHenning, Th.
dc.creatorJorgensen, U. G.
dc.creatorOtt, U.
dc.date1998-12-22
dc.date.accessioned2026-07-07T02:29:45Z
dc.date.available2026-07-07T02:29:45Z
dc.descriptionWe present here the first infrared spectra of meteoritic SiC grains. The mid-infrared transmission spectra of meteoritic SiC grains isolated from the Murchison meteorite were measured in the wavelength range 2.5--16.5 micron, in order to make available the optical properties of presolar SiC grains. These grains are most likely stellar condensates with an origin predominately in carbon stars. Measurements were performed on two different extractions of presolar SiC from the Murchison meteorite. The two samples show very different spectral appearance due to different grain size distributions. The spectral feature of the smaller meteoritic SiC grains is a relatively broad absorption band found between the longitudinal and transverse lattice vibration modes around 11.3 micron, supporting the current interpretation about the presence of SiC grains in carbon stars. In contrast to this, the spectral feature of the large (> 5 micron) grains has an extinction minimum around 10 micron. The obtained spectra are compared with commercially available SiC grains and the differences are discussed. This comparison shows that the crystal structure (e.g., beta-SiC versus alpha-SiC) of SiC grains plays a minor role on the optical signature of SiC grains compared to e.g. grain size.
dc.description7 pages, 6 figures. To appear in A&A
dc.identifierhttps://arxiv.org/abs/astro-ph/9812401
dc.identifierhttp://arxiv.org/abs/astro-ph/9812401
dc.identifier1999, A&A 343, 933
dc.identifier.urihttp://salesiana.dossiersoluciones.com/handle/123456789/13594
dc.subjectAstrophysics
dc.titleInfrared Spectra of Meteoritic SiC Grains
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