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Paper: VLTI/MIDI Observation of the Silicate Carbon Star IRAS 08002–3803: Dusty Environment Spatially Resolved for the First Time
Volume: 378, Why Galaxies Care About AGB Stars: Their Importance as Actors and Probes
Page: 327
Authors: Ohnaka, K.; Driebe, T.; Hofmann, K.-H.; Preibisch, Th.; Schertl, D.; Weigelt, G.; Wittkowski, M.
Abstract: We present the results of N–band high angular resolution observations of the silicate carbon star IRAS 08002–3803 with the MID-infrared Interferometric instrument (midi) at ESO’s Very Large Telescope Interferometer (vlti). Our vlti/midi observations of IRAS 08002–3803 have spatially resolved the dusty environment of a silicate carbon star for the first time. However, neither spherical shell models nor axisymmetric disk models consisting of silicate grains alone can simultaneously explain the observed wavelength dependence of the visibility and the spectral energy distribution (SED). We propose that the circumstellar environment of IRAS 08002–3803 may consist of two grain species coexisting in the disk: silicate and a second grain species, for which we consider amorphous carbon, large silicate grains, and metallic iron grains. Our midi observations and radiative transfer calculations lend support to a picture in which oxygen-rich material around IRAS 08002–3803 is stored in an optically thick circumbinary disk surrounding the carbon-rich primary star and its putative low-luminosity companion.
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