{
  "id": "1402.5954",
  "version": "v2",
  "published": "2014-02-24T11:21:18.000Z",
  "updated": "2014-03-03T12:25:31.000Z",
  "title": "Optically visible post-AGB/RGB stars and young stellar objects in the Small Magellanic Cloud: candidate selection, spectral energy distributions and spectroscopic examination",
  "authors": [
    "D. Kamath",
    "P. R. Wood",
    "H. Van Winckel"
  ],
  "comment": "67 pages, 26 figures, 20 tables, 3 appendices + online supporting information on CDS",
  "doi": "10.1093/mnras/stt2033",
  "categories": [
    "astro-ph.SR"
  ],
  "abstract": "We have carried out a search for optically visible post-AGB candidates in the Small Magellanic Cloud (SMC). We used mid-IR observations from the Spitzer Space Telescope to select optically visible candidates with a mid-IR excess. We obtained low-resolution optical spectra for 801 candidates. After removing contaminants and poor quality spectra, the final sample comprised of 63 post-AGB/RGB candidates of A - F spectral type. Using the spectra, we estimated the stellar parameters: effective temperature, surface gravity and [Fe/H]. We also estimated the reddening and deduced the luminosity using the stellar parameters combined with photometry. Based on a luminosity criterion, 42 of these 63 sources were classified as post-RGB candidates and the remaining as post-AGB candidates. From the spectral energy distributions we found that 6 of the 63 post-AGB/RGB candidates have a circumstellar shell suggesting that they are single stars, while 27 of them have a surrounding disc, suggesting that they are binaries. For the remaining candidates the nature of the circumstellar environment was unclear. Variability is displayed by 38 post-AGB/RGB candidates with common variability types being the Population II Cepheids (including RV-Tauri stars) and semi-regular variables. This study has also revealed a new s-process enriched RV Tauri star (J005107.19-734133.3). From the numbers of post-AGB/RGB stars in the SMC, we were able to estimate evolutionary rates that are in good agreement with the stellar evolution models with mass loss in the post-AGB phase and re-accretion in the post-RGB phase. This study also resulted in a new sample of 40 luminous young stellar objects (YSOs) of A - F spectral type. Additionally, we also identified a group of 63 objects whose spectra are dominated by emission lines and in some cases, a UV continuum. These objects are likely to be either hot post-AGB/RGBs or luminous YSOs.",
  "revisions": [
    {
      "version": "v2",
      "updated": "2014-03-03T12:25:31.000Z"
    }
  ],
  "analyses": {
    "keywords": [
      "young stellar objects",
      "small magellanic cloud",
      "spectral energy distributions",
      "optically visible post-agb/rgb stars",
      "candidate selection"
    ],
    "tags": [
      "journal article"
    ],
    "publication": {
      "journal": "Monthly Notices of the Royal Astronomical Society",
      "year": 2014,
      "month": "Apr",
      "volume": 439,
      "number": 3,
      "pages": 2211
    },
    "note": {
      "typesetting": "TeX",
      "pages": 67,
      "language": "en",
      "license": "arXiv",
      "status": "editable",
      "inspire": 1304636,
      "adsabs": "2014MNRAS.439.2211K"
    }
  }
}