{
  "id": "2303.16060",
  "version": "v1",
  "published": "2023-03-28T15:40:33.000Z",
  "updated": "2023-03-28T15:40:33.000Z",
  "title": "Distribution and Kinematics of H I through Raman He II Spectroscopy of NGC 6302",
  "authors": [
    "Seok-Jun Chang",
    "Hee-Won Lee",
    "Jiyu Kim",
    "Yeon-Ho Choi"
  ],
  "comment": "12 pages, 8 figures, accepted for publication in ApJ",
  "categories": [
    "astro-ph.SR",
    "astro-ph.GA"
  ],
  "abstract": "The young planetary nebula NGC 6302 is known to exhibit Raman-scattered He II features at 6545 and 4851 Angstrom. These features are formed through inelastic scattering of He II$\\lambda\\lambda$ 1025 and 972 with hydrogen atoms in the ground state, for which the cross sections are $1.2 \\times 10^{-21}$ and $1.4\\times 10^{-22} {\\rm\\ cm^2}$, respectively. We investigate the spectrum of NGC 6302 archived in the ESO Science Portal. Our Gaussian line fitting analysis shows that the Raman-scattered He II features are broader and more redshifted than the hypothetical model Raman features that would be formed in a cold static H I medium. We adopt a simple scattering geometry consisting of a compact He II emission region surrounded by a H I medium to perform Monte Carlo simulations using the radiative transfer code ${\\it STaRS}$. Our simulations show that the H I region is characterized by the H I column density $N_{\\rm HI}=3\\times 10^{21}{\\rm\\ cm^{-2}}$ with the random speed component $v_{\\rm ran}=10{\\rm\\ km\\ s^{-1}}$ expanding with a speed $v_{\\rm exp}= 13{\\rm\\ km\\ s^{-1}}$ from the He II emission region. Based on our best fit parameters, we estimate the H I mass of the neutral medium $M_{\\rm HI} \\simeq 1.0\\times 10^{-2}\\ {\\rm M_\\odot}$, pointing out the usefulness of Raman He II spectroscopy as a tool to trace H I components.",
  "revisions": [
    {
      "version": "v1",
      "updated": "2023-03-28T15:40:33.000Z"
    }
  ],
  "analyses": {
    "keywords": [
      "spectroscopy",
      "distribution",
      "young planetary nebula ngc",
      "kinematics",
      "emission region"
    ],
    "note": {
      "typesetting": "TeX",
      "pages": 12,
      "language": "en",
      "license": "arXiv",
      "status": "editable"
    }
  }
}