{
  "id": "1909.07738",
  "version": "v1",
  "published": "2019-09-17T12:03:25.000Z",
  "updated": "2019-09-17T12:03:25.000Z",
  "title": "C-type shock modelling -- the effect of new H$_2$-H collisional rate coefficients",
  "authors": [
    "A. V. Nesterenok",
    "D. Bossion",
    "Y. Scribano",
    "F. Lique"
  ],
  "comment": "10 pages, 4 figures, accepted for publication in MNRAS",
  "doi": "10.1093/mnras/stz2441",
  "categories": [
    "astro-ph.GA"
  ],
  "abstract": "We consider collisional excitation of H$_2$ molecules in C-type shocks propagating in dense molecular clouds. New data on collisional rate coefficients for (de-)excitation of H$_2$ molecule in collisions with H atoms and new H$_2$ dissociation rates are used. The new H$_2$-H collisional data are state of the art and are based on the most accurate H$_3$ potential energy surface. We re-examine the excitation of rotational levels of H$_2$ molecule, the para-to-ortho-H$_2$ conversion, and H$_2$ dissociation by H$_2$-H collisions. At cosmic ray ionization rates $\\zeta \\geq 10^{-16}$ s$^{-1}$ and at moderate shock speeds, the H/H$_2$ ratio at the shock front is mainly determined by the cosmic ray ionization rate. The H$_2$-H collisions play the main role in the para-to-ortho-H$_2$ conversion and, at $\\zeta \\geq 10^{-15}$ s$^{-1}$, in the excitation of vibrationally excited states of H$_2$ molecule in the shock. The H$_2$ ortho-to-para ratio (OPR) of the shocked gas and column densities of rotational levels of vibrationally excited states of H$_2$ are found to depend strongly on the cosmic ray ionization rate. We discuss the applicability of the presented results to interpretation of observations of H$_2$ emission in supernova remnants.",
  "revisions": [
    {
      "version": "v1",
      "updated": "2019-09-17T12:03:25.000Z"
    }
  ],
  "analyses": {
    "keywords": [
      "collisional rate coefficients",
      "cosmic ray ionization rate",
      "c-type shock modelling",
      "rotational levels",
      "vibrationally excited states"
    ],
    "tags": [
      "journal article"
    ],
    "note": {
      "typesetting": "TeX",
      "pages": 10,
      "language": "en",
      "license": "arXiv",
      "status": "editable"
    }
  }
}