{
  "id": "1904.07215",
  "version": "v1",
  "published": "2019-04-15T17:48:08.000Z",
  "updated": "2019-04-15T17:48:08.000Z",
  "title": "The surprisingly low carbon mass in the debris disk around HD 32297",
  "authors": [
    "Gianni Cataldi",
    "Yanqin Wu",
    "Nagayoshi Ohashi",
    "Alexis Brandeker",
    "Attila Moór",
    "Péter Ábrahám",
    "Ruben Asensio-Torres",
    "Maria Cavallius",
    "Bill Dent",
    "Carol Grady",
    "Thomas Henning",
    "Aya E. Higuchi",
    "A. Meredith Hughes",
    "Markus Janson",
    "Inga Kamp",
    "Ágnes Kóspál",
    "Göran Olofsson",
    "Seth Redfield",
    "Aki Roberge",
    "Alycia Weinberger",
    "Barry Welsh"
  ],
  "comment": "submitted to ApJ",
  "categories": [
    "astro-ph.EP"
  ],
  "abstract": "Gas has been detected in a number of debris disks. It is likely secondary in nature and produced by the colliding solids in these disks. Here, we used ALMA Band 8 to observe emission from neutral carbon at 492 GHz in the CO-rich debris disk around the 15-30 Myr old A-type star HD 32297. We find that C$^0$ is located in a ring at $\\sim$110 au with a FWHM of $\\sim$80 au, and with a surprisingly small mass of $(3.5\\pm0.2)\\times10^{-3}$ M$_\\oplus$. An order of magnitude estimate shows that such a mass can be produced by CO photo-dissociation in a time no longer than $10,000$ yr. We develop a simple evolutionary model to properly account for the reduction in CO photo-dissociation by CO self-shielding and shielding by neutral carbon, following the suggestion by Kral et al (2018). When adopting the commonly used intensity of the interstellar radiation field, to simultaneously reproduce the observed C$^0$ and the previously determined C$^{18}$O masses with our model, a high CO production rate by the debris disk is required, and that gas production started only $\\sim$3000 yr ago around this star. By association, its dusty debris disk must also be similarly short-lived. We discuss various scenarios where our conclusion may fail. We conclude that the gas observed around HD 32297 is the result of a recent event, similar to the debris disk around $\\beta$ Pictoris.",
  "revisions": [
    {
      "version": "v1",
      "updated": "2019-04-15T17:48:08.000Z"
    }
  ],
  "analyses": {
    "keywords": [
      "debris disk",
      "surprisingly low carbon mass",
      "myr old a-type star hd",
      "neutral carbon",
      "interstellar radiation field"
    ],
    "note": {
      "typesetting": "TeX",
      "pages": 0,
      "language": "en",
      "license": "arXiv",
      "status": "editable"
    }
  }
}