{
  "id": "1601.04710",
  "version": "v1",
  "published": "2016-01-18T21:00:04.000Z",
  "updated": "2016-01-18T21:00:04.000Z",
  "title": "The evolved-star dust budget of the Small Magellanic Cloud: the critical role of a few key players",
  "authors": [
    "Sundar Srinivasan",
    "Martha L. Boyer",
    "Francisca Kemper",
    "Margaret Meixner",
    "David Riebel",
    "Benjamin A. Sargent"
  ],
  "comment": "28 pages, 22 figures, accepted for publication in MNRAS",
  "categories": [
    "astro-ph.SR",
    "astro-ph.GA"
  ],
  "abstract": "The lifecycle of dust in the interstellar medium (ISM) is heavily influenced by outflows from asymptotic giant branch (AGB) and red supergiant (RSG) stars, a large fraction of which is contributed by a few very dusty sources. We compute the dust input to the Small Magellanic Cloud (SMC) by fitting the multi-epoch mid-infrared spectral energy distributions (SEDs) of AGB/RSG candidates with models from the {\\em G}rid of {\\em R}SG and {\\em A}GB {\\em M}odel{\\em S} (GRAMS) grid, allowing us to estimate the luminosities and dust-production rates (DPRs) of the entire population. By removing contaminants, we guarantee a high-quality dataset with reliable DPRs and a complete inventory of the dustiest sources. We find a global AGB/RSG dust-injection rate of $(1.3\\pm 0.1)\\times 10^{-6}$ \\msunperyr, in agreement with estimates derived from mid-infrared colours and excess fluxes. As in the LMC, a majority (66\\%) of the dust arises from the extreme AGB stars, which comprise only $\\approx$7\\% of our sample. A handful of far-infrared sources, whose 24 \\mic\\ fluxes exceed their 8 \\mic\\ fluxes, dominate the dust input. Their inclusion boosts the global DPR by $\\approx$1.5$\\times$, making it necessary to determine whether they are AGB stars. Model assumptions, rather than missing data, are the major sources of uncertainty; depending on the choice of dust shell expansion speed and dust optical constants, the global DPR can be up to $\\approx$10 times higher. Our results suggest a non-stellar origin for the SMC dust, barring as yet undiscovered evolved stars with very high DPRs.",
  "revisions": [
    {
      "version": "v1",
      "updated": "2016-01-18T21:00:04.000Z"
    }
  ],
  "analyses": {
    "keywords": [
      "small magellanic cloud",
      "evolved-star dust budget",
      "critical role",
      "mid-infrared spectral energy distributions",
      "agb stars"
    ],
    "note": {
      "typesetting": "TeX",
      "pages": 28,
      "language": "en",
      "license": "arXiv",
      "status": "editable"
    }
  }
}