The 21 micron and 30 micron circumstellar dust features in evolved C-rich objects

Abstract

The 21micron and 30micron bands are the strongest dust emission features detected in evolved low- and intermediate-mass C-rich stars (i.e. asymptotic giant branch [AGB] stars, proto-planetary nebulae [PPN], and planetary nebulae [PN]). While the 21micron feature is rare and exists only in the transient PPN phase, the 30micron feature is more common and seen in the entire late stage of stellar evolution, from AGB to PPN and PN phases, as well as in the low-metallicity galaxies: the Large Magellanic Cloud (LMC) and the Small Magellanic Cloud (SMC). The carriers of these features remain unidentified. Eleven of the twelve well-identified 21micron sources also emit in the 30micron band, suggesting that their carriers may be somewhat related.

7 pages, 1 figure, uses eps.cls. Accepted for publication in "Earth, Planets and Space" (special issue on Cosmic Dust)

References in corpus (4)

• A Spitzer mid-infrared spectral survey of mass-losing carbon stars in the Large Magellanic Cloud
• Spitzer spectroscopy of carbon stars in the Small Magellanic Cloud
• A Spitzer Study of 21 and 30 Micron Emission in Several Galactic Carbon-rich Proto-Planetary Nebulae
• Condensation of MgS in outflows from carbon stars

Cited by in corpus (4)

• On Iron Monoxide Nanoparticles as a Carrier of the Mysterious 21 Micrometer Emission Feature in Post-Asymptotic Giant Branch Stars
• On the Relation between the Mysterious 21 Micrometer Emission Feature of Post-Asymptotic Giant Branch Stars and Their Mass Loss Rates
• A Tale of Three Mysterious Spectral Features in Carbon-Rich Evolved Stars: The 21 Micrometer, 30 Micrometer, and "Unidentified Infrared" Emission Features
• Are fulleranes responsible for the 21 micron feature?