{
  "id": "1907.00571",
  "version": "v1",
  "published": "2019-07-01T06:55:02.000Z",
  "updated": "2019-07-01T06:55:02.000Z",
  "title": "New constraints on the dust and gas distribution in the LkCa 15 disk from ALMA",
  "authors": [
    "Sheng Jin",
    "Andrea Isella",
    "Pinghui Huang",
    "Shengtai Li",
    "Hui Li",
    "Jianghui Ji"
  ],
  "comment": "17 pages, 9 figures, accepted for publication in ApJ",
  "categories": [
    "astro-ph.EP"
  ],
  "abstract": "We search a large parameter space of the LkCa 15's disk density profile to fit its observed radial intensity profile of $^{12}$CO (J = 3-2) obtained from ALMA. The best-fit model within the parameter space has a disk mass of 0.1 $M_{\\odot}$ (using an abundance ratio of $^{12}$CO/H$_2$ $=$ 1.4 $\\times 10^{-4}$ in mass), an inner cavity of 45 AU in radius, an outer edge at $\\sim$ 600 AU, and a disk surface density profile follows a power-law of the form $\\rho_r \\propto r^{-4}$. For the disk density profiles that can lead to a small reduced $\\chi^2$ of goodness-of-fit, we find that there is a clear linear correlation between the disk mass and the power-law index $\\gamma$ in the equation of disk density profile. This suggests that the $^{12}$CO disk of LkCa 15 is optically thick and we can fit its $^{12}$CO radial intensity profile using either a lower disk mass with a smaller $\\gamma$ or a higher disk mass with a bigger $\\gamma$. By comparing the $^{12}$CO channel maps of the best-fit model with disk models with higher or lower masses, we find that a disk mass of $\\sim$ 0.1 $M_{\\odot}$ can best reproduce the observed morphology of the $^{12}$CO channel maps. The dust continuum map at 0.87 mm of the LkCa 15 disk shows an inner cavity of the similar size of the best-fit gas model, but its out edge is at $\\sim$ 200 AU, much smaller than the fitted gas disk. Such a discrepancy between the outer edges of the gas and dust disks is consistent with dust drifting and trapping models.",
  "revisions": [
    {
      "version": "v1",
      "updated": "2019-07-01T06:55:02.000Z"
    }
  ],
  "analyses": {
    "keywords": [
      "disk mass",
      "gas distribution",
      "15s disk density profile",
      "constraints",
      "radial intensity profile"
    ],
    "note": {
      "typesetting": "TeX",
      "pages": 17,
      "language": "en",
      "license": "arXiv",
      "status": "editable"
    }
  }
}