Investigation of Mid-infrared Dust Spectral Features of Oxygen-rich AGB Star
Abstract
Understanding cosmic dust and its origins furthers understanding into the evolution of stellar objects in the universe. Asymptotic Giant Branch (ABG) stars, being major contributors to the interstellar dust through their mass ejections, offers an opportunity to study stellar evolution and the impact of dust on its environment. We have investigated the oxygen-rich Mira variable star R Cas via radiative transfer modeling and infrared spectroscopic observations, taken with the Infrared Space Observatory (ISO), and the Infrared Astronomical Satellite (IRAS). Using DUSTY, a 1-d radiative transfer code, we have created models of the cosmic ejector from this AGB star. Because radiative transfer modeling is inherently degenerate, we sought ways to constrain the model input variables. Using previously determined stellar parameters, such as mass-loss rate and expansion velocity for R Cas, we estimate the condensation temperatures for various potential astrominerals. Using the published photometric data to constrain the visible and near-infrared portions of the star's spectral energy distribution, we aimed to match the observed spectroscopic data and determine to composition and density of the dust surrounding R Cas. Here we present preliminary models of the dust composition and discuss the methodologies for constraining model parameters.
- Publication:
-
American Astronomical Society Meeting Abstracts #234
- Pub Date:
- June 2019
- Bibcode:
- 2019AAS...23420103H