Carbon-rich dust from the asymptotic giant branch to planetary nebulae

G.C. Sloan (UNC, STScI, Cornell)

2017, Planetery and Space Sci., 149, 32

Full manuscript available locally (PDF).

This paper resulted from an invited review presented at the Cosmic Dust IX meeting in Sendai, Japan, in August, 2016.

As carbon stars evolve from the asymptotic giant branch to planetary nebulae, the spectrum from dust around them changes from a mixture dominated by amorphous carbon to one dominated by polycyclic aromatic hydrocarbons (PAHs). Along the way, many other components appear, including SiC and MgS, aliphatic hydrocarbons, the still unidentified 21 µm emission feature, and fullereness. The evidence from infrared spectral surveys suggests that the dust can form with layered structures, that aliphatics can co-exist with the PAHs in post-AGB objects, and that the appearance of the 21 µm feature is associated with aliphatics. Many uncertainties remain. Perhaps the most important is the composition of the amorphous carbon that dominates dust on the AGB, because different compositions can change the total dust output from carbon stars by nearly an order of magnitude.

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Last modified 3 January, 2018. © Gregory C. Sloan and others.