{
  "id": "1510.07063",
  "version": "v1",
  "published": "2015-10-09T09:29:29.000Z",
  "updated": "2015-10-09T09:29:29.000Z",
  "title": "Filament Fragmentation in High-Mass Star Formation",
  "authors": [
    "H. Beuther",
    "S. E. Ragan",
    "K. Johnston",
    "Th. Henning",
    "A. Hacar",
    "J. T. Kainulainen"
  ],
  "comment": "12 pages, 9 figures, accepted for A&A, a higher-resolution version can be found at http://www.mpia.de/homes/beuther/papers.html",
  "categories": [
    "astro-ph.GA",
    "astro-ph.SR"
  ],
  "abstract": "Aims: We resolve the length-scales for filament formation and fragmentation (res. <=0.1pc), in particular the Jeans length and cylinder fragmentation scale. Methods: We observed the prototypical high-mass star-forming filament IRDC18223 with the Plateau de Bure Interferometer (PdBI) in the 3.2mm continuum and N2H+(1-0) line emission in a ten field mosaic at a spatial resolution of ~4'' (~14000AU). Results: The dust continuum emission resolves the filament into a chain of at least 12 relatively regularly spaced cores. The mean separation between cores is ~0.40(+-0.18)pc. While this is approximately consistent with the fragmentation of an infinite, isothermal, gravitationally bound gas cylinder, a high mass-to-length ratio of M/l~1000M_sun/pc requires additional turbulent and/or magnetic support against radial collapse of the filament. The N2H+(1-0) data reveal a velocity gradient perpendicular to the main filament. Although rotation of the filament cannot be excluded, the data are also consistent with the main filament being comprised of several velocity-coherent sub-filaments. Furthermore, this velocity gradient perpendicular to the filament resembles recent results toward Serpens south that are interpreted as signatures of filament formation within magnetized and turbulent sheet-like structures. Lower-density gas tracers ([CI] and C18O) reveal a similar red/blueshifted velocity structure on scales around 60'' east and west of the IRDC18223 filament. This may tentatively be interpreted as a signature of the large-scale cloud and the smaller-scale filament being kinematically coupled. We do not identify a velocity gradient along the axis of the filament. This may either be due to no significant gas flows along the filamentary axis, but it may partly also be caused by a low inclination angle of the filament with respect to the plane of the sky that could minimize such signature.",
  "revisions": [
    {
      "version": "v1",
      "updated": "2015-10-09T09:29:29.000Z"
    }
  ],
  "analyses": {
    "keywords": [
      "high-mass star formation",
      "filament fragmentation",
      "high-mass star-forming filament irdc18223",
      "velocity gradient perpendicular",
      "filament formation"
    ],
    "note": {
      "typesetting": "TeX",
      "pages": 12,
      "language": "en",
      "license": "arXiv",
      "status": "editable"
    }
  }
}