Dust in AGB Stars: Transparent or Opaque?
2011 (English)In: Why Galaxies Care about AGB Stars II: Shining Examples and Common Inhabitants, 2011, Vol. 445Conference paper (Refereed)
The optical properties of the dust particles that drive the winds of cool giant stars affect the stellar spectra in two ways: (1) indirectly, through their influence on the dynamical structure of the atmosphere/envelope and the resulting molecular features, and (2) directly, by changes of the spectral energy distribution due to absorption and scattering on dust grains. The qualitative differences in the energy distributions of C-type and M-type AGB stars in the visual and near-infrared regions suggest that the dust particles in oxygen rich atmospheres are relatively transparent to radiation. By using detailed dynamical models of gas and radiation combined with a simple description for the dust opacity (which can be adjusted to mimic different wavelength dependences and condensation temperatures) and also by adjusting the fraction of the opacity that is treated as true absorption, we investigate which dust properties produce synthetic photometry consistent with observations. The goal of this study is to narrow down the possible dust species that may be driving the winds in M-type AGB stars.
Place, publisher, year, edition, pages
2011. Vol. 445
, Astronomical Society of the Pacific Conference Series
Astronomy, Astrophysics and Cosmology
IdentifiersURN: urn:nbn:se:uu:diva-170170OAI: oai:DiVA.org:uu-170170DiVA: diva2:508579
Astronomical Society of the Pacific Conference Series, 445