{
  "id": "1003.3100",
  "version": "v1",
  "published": "2010-03-16T08:13:04.000Z",
  "updated": "2010-03-16T08:13:04.000Z",
  "title": "Determining the forsterite abundance of the dust around Asymptotic Giant Branch stars",
  "authors": [
    "B. L. de Vries",
    "M. Min",
    "L. B. F. M. Waters",
    "J. A. D. L. Blommaert",
    "F. Kemper"
  ],
  "comment": "Accepted for publication in A&A",
  "categories": [
    "astro-ph.SR"
  ],
  "abstract": "Aims. We present a diagnostic tool to determine the abundance of the crystalline silicate forsterite in AGB stars surrounded by a thick shell of silicate dust. Using six infrared spectra of high mass-loss oxygen rich AGB stars we obtain the forsterite abundance of their dust shells. Methods. We use a monte carlo radiative transfer code to calculate infrared spectra of dust enshrouded AGB stars. We vary the dust composition, mass-loss rate and outer radius. We focus on the strength of the 11.3 and the 33.6 \\mu m forsterite bands, that probe the most recent (11.3 \\mu m) and older (33.6 \\mu m) mass-loss history of the star. Simple diagnostic diagrams are derived, allowing direct comparison to observed band strengths. Results. Our analysis shows that the 11.3 \\mu m forsterite band is a robust indicator for the forsterite abundance of the current mass-loss period for AGB stars with an optically thick dust shell. The 33.6 \\mu m band of forsterite is sensitive to changes in the density and the geometry of the emitting dust shell, and so a less robust indicator. Applying our method to six high mass-loss rate AGB stars shows that AGB stars can have forsterite abundances of 12% by mass and higher, which is more than the previously found maximum abundance of 5%.",
  "revisions": [
    {
      "version": "v1",
      "updated": "2010-03-16T08:13:04.000Z"
    }
  ],
  "analyses": {
    "keywords": [
      "asymptotic giant branch stars",
      "forsterite abundance",
      "mass-loss oxygen rich agb",
      "mass-loss rate agb stars",
      "oxygen rich agb stars"
    ],
    "tags": [
      "journal article"
    ],
    "publication": {
      "doi": "10.1051/0004-6361/200913588",
      "journal": "Astronomy and Astrophysics",
      "year": 2010,
      "month": "Jun",
      "volume": 516
    },
    "note": {
      "typesetting": "TeX",
      "pages": 0,
      "language": "en",
      "license": "arXiv",
      "status": "editable",
      "inspire": 849063,
      "adsabs": "2010A&A...516A..86D"
    }
  }
}