Chemical depletion in the Large Magellanic Cloud: RV Tauri stars and the photospheric feedback from their dusty discs - Astrophysics > Solar and Stellar AstrophysicsReport as inadecuate




Chemical depletion in the Large Magellanic Cloud: RV Tauri stars and the photospheric feedback from their dusty discs - Astrophysics > Solar and Stellar Astrophysics - Download this document for free, or read online. Document in PDF available to download.

Abstract: Aims: By studying the photospheric abundances of 4 RV Tauri stars in the LMC,we test whether the depletion pattern of refractory elements, seen in similarGalactic sources, is also common for extragalactic sources. Since thisdepletion process probably only occurs through interaction with a stable disc,we investigate the circumstellar environment of these sources. Methods: Adetailed photospheric abundance study was performed using high-resolution UVESoptical spectra. To study the circumstellar environment we use photometric datato construct the spectral energy distributions of the stars, and determine thegeometry of the circumstellar environment, whereas low-resolution Spitzer-IRSinfrared spectra are used to trace its mineralogy. Results: Our results showthat, also in the LMC, the photospheres of RV Tauri stars are commonly affectedby the depletion process, although it can differ significantly in strength fromsource to source. From our detailed disc modelling and mineralogy study, wefind that this process, as in the Galaxy, appears closely related to thepresence of a stable Keplerian disc. The newly studied extragalactic objectshave similar observational characteristics as Galactic post-AGB binariessurrounded by a dusty disc, and are therefore also believed to be part of abinary system. One source shows a very small infrared excess, atypical for adisc source, but still has evidence for depletion. We speculate this couldpoint to the presence of a very evolved disc, similar to debris discs seenaround young stellar objects.



Author: C. Gielen, H. Van Winckel, M. Reyniers, A. Zijlstra, T. Lloyd Evans, K.D. Gordon, F. Kemper, R. Indebetouw, M. Marengo, M. Matsuu

Source: https://arxiv.org/



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