Silicon carbide dust grains are ubiquitous in circumstellar envelopes around C-rich AGB stars. However, the main gas-phase precursors leading to the formation of SiC dust have not yet been identified. To date, only three molecules containing an Si--C bond have been identified to have significant abundances in C-rich AGB stars: SiC2, SiC, and Si2C. The ring molecule SiC2 has been observed in a handful of evolved stars, while SiC and Si2C have only been detected in the C-star envelope IRC +10216. We aim to study how widespread and abundant SiC2, SiC, and Si2C are in envelopes around C-rich AGB stars and whether or not these species play an active role as gas-phase precursors of silicon carbide dust in the ejecta of carbon stars.
@article{arxiv.1708.00307,
title = {The Abundance of SiC$_2$ in Carbon Star Envelopes},
author = {Sarah Massalkhi and M. Agúndez and J. Cernicharo and J. P. Fonfría and M. Santander-García},
journal= {arXiv preprint arXiv:1708.00307},
year = {2018}
}
Comments
Poster presentation to be published in: Proceedings of the IAU Symposium No. 332, 2017, Puerto Varas, Chile. M. Cunningham, T. Millar and Y. Aikawa, eds., (10 pages, 5 figures, 2 tables)