Shared more. Cited more. Safe forever.
    • advanced search
    • submit works
    • about
    • help
    • contact us
    • login
    View Item 
    •   MOspace Home
    • University of Missouri-Columbia
    • College of Arts and Sciences (MU)
    • Department of Physics and Astronomy (MU)
    • Physics and Astronomy publications (MU)
    • View Item
    •   MOspace Home
    • University of Missouri-Columbia
    • College of Arts and Sciences (MU)
    • Department of Physics and Astronomy (MU)
    • Physics and Astronomy publications (MU)
    • View Item
    JavaScript is disabled for your browser. Some features of this site may not work without it.
    advanced searchsubmit worksabouthelpcontact us

    Browse

    All of MOspaceCommunities & CollectionsDate IssuedAuthor/ContributorTitleIdentifierThesis DepartmentThesis AdvisorThesis SemesterThis CollectionDate IssuedAuthor/ContributorTitleIdentifierThesis DepartmentThesis AdvisorThesis Semester

    Statistics

    Most Popular ItemsStatistics by CountryMost Popular AuthorsStatistics by Referrer

    On Silicon Carbide Grains as the Carrier of the 21 Micron Emission Feature in Post-Asymptotic Giant Branch Stars

    Jiang, B. W.
    Zhang, Ke
    Li, Aigen
    View/Open
    [PDF] OnSiliconCarbideGrains.pdf (114.2Kb)
    Date
    2005
    Format
    Article
    Metadata
    [+] Show full item record
    Abstract
    The mysterious 21 mm emission feature seen in 12 proto-planetary nebulae remains unidentified since its first detection in 1989. Over a dozen candidate materials have been proposed within the past decade, but none of them have received general acceptance. Very recently, silicon carbide (SiC) grains with impurities were suggested to be the carrier of this enigmatic feature, based on recent laboratory data that doped SiC grains exhibit a resonance at ∼21 mm. This proposal gains strength from the fact that SiC is a common dust species in carbon-rich circumstellar envelopes. However, SiC dust has a strong vibrational band at ∼11.3 mm. We show in this Letter that in order to be consistent with the observed flux ratios of the 11.3 mm feature to the 21 mm feature, the band strength of the 21 mm resonance has to be very strong, too strong to be consistent with current laboratory measurements. But this does not yet readily rule out the SiC hypothesis since recent experimental results have demonstrated that the 21 mm resonance of doped SiC becomes stronger as the C impurity increases. Further laboratory measurements of SiC dust with high fractions of C impurity are urgently needed to test the hypothesis of SiC as the carrier of the 21 mm feature.
    URI
    http://hdl.handle.net/10355/5187
    Citation
    The Astrophysical Journal, 630:L77-L80, 2005 September 1
    Collections
    • Physics and Astronomy publications (MU)

    Send Feedback
    hosted by University of Missouri Library Systems
     

     


    Send Feedback
    hosted by University of Missouri Library Systems