{
  "id": "1911.05877",
  "version": "v1",
  "published": "2019-11-14T00:56:17.000Z",
  "updated": "2019-11-14T00:56:17.000Z",
  "title": "The Giant Herbig-Haro Flow HH 212 and Associated Star Formation",
  "authors": [
    "Bo Reipurth",
    "C. J. Davis",
    "John Bally",
    "A. C. Raga",
    "B. P. Bowler",
    "T. R. Geballe",
    "Colin Aspin",
    "Hsin-Fang Chiang"
  ],
  "comment": "17 pages, 10 figures, 2 tables",
  "journal": "Astron. J. 158:107, 2019",
  "categories": [
    "astro-ph.SR",
    "astro-ph.GA"
  ],
  "abstract": "The bipolar jet HH 212, among the finest collimated jets known, has so far been detected only in near-infrared H$_2$ emission. Here we present deep optical images that show two of the major bow shocks weakly detected in optical [SII] emission, as expected for a bona fide Herbig-Haro jet. We present widefield H$_2$ images which reveal two more bow shocks located symmetrically around the source and along the main jet axis. Additionally, examination of Spitzer 4.5 $\\mu$m images reveals yet another bright bow shock further to the north along the jet axis; no corresponding bow shock is seen to the south. In total, the HH 212 flow has an extent of 1050 arcsec, corresponding to a projected dimension of 2.0 pc. HH 212 thus joins the growing group of parsec-scale Herbig-Haro jets. Proper motion measurements indicate a velocity of about 170 km/sec, highly symmetric around the source, with an uncertainty of $\\sim$30 km/sec, suggesting a probable age of the giant HH 212 flow of about 7000 yr. The jet is driven by a deeply embedded source, known as IRAS 05413-0104. We draw attention to a Spitzer near- and mid-infrared source, which we call IRS-B, located only 7 arcsec from the driving source, towards the outskirts of the dense cloud core. Infrared photometry and spectroscopy suggests that IRS-B is a K-type star with a substantial infrared excess, except that for an extinction of A$_V$ = 44 the star would have only a weakinfrared excess, and so in principle it could be a K-giant at a distance of about 2 kpc.",
  "revisions": [
    {
      "version": "v1",
      "updated": "2019-11-14T00:56:17.000Z"
    }
  ],
  "analyses": {
    "keywords": [
      "giant herbig-haro flow hh",
      "associated star formation",
      "jet axis",
      "bona fide herbig-haro jet",
      "major bow shocks"
    ],
    "tags": [
      "journal article"
    ],
    "note": {
      "typesetting": "TeX",
      "pages": 17,
      "language": "en",
      "license": "arXiv",
      "status": "editable"
    }
  }
}