{
  "id": "1808.10184",
  "version": "v1",
  "published": "2018-08-30T08:46:23.000Z",
  "updated": "2018-08-30T08:46:23.000Z",
  "title": "H2 chemistry in galaxy simulations: an improved supernova feedback model",
  "authors": [
    "Alessandro Lupi"
  ],
  "comment": "14 pages, 19 figures, submitted",
  "categories": [
    "astro-ph.GA",
    "astro-ph.CO"
  ],
  "abstract": "In this study, we present a new, physically motivated sub-grid prescription for supernova feedback, which accounts for the unresolved energy-conserving phase of the bubble expansion. We implement this model in the mesh-less hydrodynamic code GIZMO, coupled with the chemistry library krome, and we validate it against different setups, to address how it affects the formation/dissociation of molecular hydrogen (H2). First, we test the model in very idealised conditions, to show that it can accurately reproduce the terminal momentum of the blast-wave independent of resolution. Then, we apply it to a suite of numerical simulations of an isolated Milky Way-like galaxy and compare it with a similar run employing the delayed-cooling sub-grid prescription. We find that the delayed-cooling model, by pressurising ad-hoc the gas, is more effective in suppressing star formation. However, to get this effect, it must maintain the gas warm/hot at densities where it is expected to cool efficiently, artificially changing the thermo-chemical state of the gas, and reducing the H2 abundance even in dense gas. Mechanical feedback, on the other hand, is able to reproduce observed correlations like the Kennicutt-Schmidt relation and the H2 column densities without altering the gas thermodynamics, and, at the same time, can drive more powerful outflows. Finally, we show that the model is consistent at different resolution levels, with only mild differences.",
  "revisions": [
    {
      "version": "v1",
      "updated": "2018-08-30T08:46:23.000Z"
    }
  ],
  "analyses": {
    "keywords": [
      "supernova feedback model",
      "galaxy simulations",
      "h2 chemistry",
      "mesh-less hydrodynamic code gizmo",
      "chemistry library krome"
    ],
    "note": {
      "typesetting": "TeX",
      "pages": 14,
      "language": "en",
      "license": "arXiv",
      "status": "editable"
    }
  }
}