1996/07/25 by M. Marengo, G. Canil, Marengo, M. +9
Physics and Astronomy · #Astro and Planetary Science #Astronomy and Astrophysical Research #Astrophysics (astro-ph) #Astrophysics and Star Formation Studies #FOS: Physical sciences #Stellar, planetary, and galactic studies #astro-ph
paper · pdf · doi:10.48550/arxiv.astro-ph/9607129
19 pages, LaTex, 5 Postscript figures, uses psfig.sty Submitted to Astronomy and Astrophysics. Gzipped Compressed Postscript also available at http://www.sissa.it/~marengo/sci/tirpap2/tirpap2.ps.gz
arxiv created 1996/07/25 · openalex publication_date 1996/07/25 · arxiv updated 2009/12/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
Radiative transfer modelling of AGB circumstellar envelopes is applied to a\nsample of AGB stars previously observed with the mid-IR imaging camera TIRCAM\n(Busso et al. 1996: Paper I). We present the results of our simulations, aimed\nat deriving the physical parameters of the envelope, such as the optical depth\nand the radial thermal structure, the mass loss and the dust-to-gas mass ratio.\nThe chemical composition of the dust in the observed envelopes is discussed.\nThe ability of different sets of dust opacities to fit the mid-infrared spectra\nis evaluated. The hypothesis of dust grain aging and annealing in O-rich\nenvelopes is considered in order to explain an apparent inadequacy of the\navailabe opacities to describe the variety of observed spectra, as previously\nnoted by other authors. Various possible origins of the discrepancies are\ndiscussed, together with their consequences on the dust grain formation\nprocesses.\n