{
  "id": "2305.13449",
  "version": "v1",
  "published": "2023-05-22T19:49:13.000Z",
  "updated": "2023-05-22T19:49:13.000Z",
  "title": "Interstellar Bow Shocks around Fast Stars Passing through the Local Interstellar Medium",
  "authors": [
    "J. Michael Shull",
    "S. R. Kulkarni"
  ],
  "comment": "Accepted to Astrophysical Journal, 12 pages with one table",
  "categories": [
    "astro-ph.GA",
    "astro-ph.SR"
  ],
  "abstract": "Bow-shocks are produced in the local interstellar medium by the passage of fast stars from the Galactic thin-disk and thick-disk populations with velocities $V_* = $ 40-80 km/s. Stellar transits of local H I clouds occur every 3500-7000 yr on average and last between $10^4$ and $10^5$ yr. There could be 10-20 active bow shocks around low-mass stars inside clouds within 10-15 pc of the Sun. At local cloud distances of 3-10 pc, their turbulent wakes have transverse radial extents $R_{\\rm wake} \\approx$ 10-300 AU, angular sizes 10-100 arcsec, and Lyman-alpha surface brightnesses of 2-8 Rayleighs in gas with total hydrogen density $n_H \\approx 0.1~{\\rm cm}^{-3}$ and $V_* =$ 40-80 km/s. These transit wakes may cover an area fraction $f_A \\approx (R_{\\rm wake}/R_{\\rm cl}) \\approx 10^{-3}$ of local H I clouds and be detectable in IR (dust), UV (Lya, two-photon), or non-thermal radio emission. Turbulent heating in these wakes could produce the observed elevated rotational populations of H$_2$ ($J \\geq 2$) and influence the endothermic formation of CH$^+$ in diffuse interstellar gas at $T > 10^3$ K.",
  "revisions": [
    {
      "version": "v1",
      "updated": "2023-05-22T19:49:13.000Z"
    }
  ],
  "analyses": {
    "keywords": [
      "local interstellar medium",
      "interstellar bow shocks",
      "fast stars passing",
      "low-mass stars inside clouds",
      "lyman-alpha surface brightnesses"
    ],
    "note": {
      "typesetting": "TeX",
      "pages": 12,
      "language": "en",
      "license": "arXiv",
      "status": "editable"
    }
  }
}