{
  "id": "1701.04331",
  "version": "v1",
  "published": "2017-01-16T15:39:26.000Z",
  "updated": "2017-01-16T15:39:26.000Z",
  "title": "The adventure of carbon stars - Observations and modelling of a set of C-rich AGB stars",
  "authors": [
    "Gioia Rau",
    "Josef Hron",
    "Claudia Paladini",
    "Benard Aringer",
    "Kjell Eriksson",
    "Paola Marigo",
    "Walter Nowotny",
    "Rebekka Grellmann"
  ],
  "comment": "22 pages. Accepted for publication in A&A",
  "categories": [
    "astro-ph.SR"
  ],
  "abstract": "Modeling stellar atmospheres is a complex, intriguing task in modern astronomy. A systematic comparison of models with multi-technique observations is the only efficient way to constrain them. Aims: We performed a self-consistent modeling of the atmospheres of six C-rich AGB stars: R Lep, R Vol, Y Pav, AQ Sgr, U Hya and X TrA, with the aim of enlarging the knowledge of the dynamic processes occurring in their atmospheres. Methods. We used VLTI/MIDI interferometric observations, in combination with spectro-photometric data, and compared them with self-consistent dynamic models atmospheres. Results: The models can reproduce SED data well at wavelengths longwards of 1{\\mu}m, and the interferometric observations between 8{\\mu}m and 10{\\mu}m. Discrepancies could be due to a combination of data- and model-related effects. The models best fitting the Miras are significantly extended, with a prominent shell-like structure, while the models best fitting the non-Miras are more compact, showing lower average mass-loss. The mass loss is of episodic or multi-periodic nature, but causes the visual amplitudes to be notably larger than the observed ones. Stellar parameters were derived from the model fitting: T_eff, L_bol, M, C/O, $\\dot{\\text{M}}$. Our findings agree well with literature values within the uncertainties. T_eff and L_bol are also in good agreement with the T derived from the angular diameter {\\theta}_{(V-K)} and L_bol from the SED fitting, except for AQ Sgr. Finally, {\\theta}_Ross and {\\theta}_(V-K) agree with each other better for the Miras than for the non-Miras,which is probably connected to the episodic nature of the latter models. We also located the stars in the H-R diagram, comparing them with evolutionary tracks. We found that the main derived properties from the model fitting are in good agreement with TP-AGB evolutionary calculations for carbon stars (COLIBRI code).",
  "revisions": [
    {
      "version": "v1",
      "updated": "2017-01-16T15:39:26.000Z"
    }
  ],
  "analyses": {
    "keywords": [
      "c-rich agb stars",
      "carbon stars",
      "models best fitting",
      "self-consistent dynamic models atmospheres",
      "aq sgr"
    ],
    "note": {
      "typesetting": "TeX",
      "pages": 22,
      "language": "en",
      "license": "arXiv",
      "status": "editable"
    }
  }
}