{
  "id": "1107.3616",
  "version": "v1",
  "published": "2011-07-19T02:55:30.000Z",
  "updated": "2011-07-19T02:55:30.000Z",
  "title": "Clustered Star Formation in Magnetic Clouds: Properties of Dense Cores Formed in Outflow-Driven Turbulence",
  "authors": [
    "Fumitaka Nakamura",
    "Zhi-Yun Li"
  ],
  "comment": "49 pages, 16 figures accepted by The Astrophysical Journal",
  "categories": [
    "astro-ph.SR",
    "astro-ph.GA"
  ],
  "abstract": "We investigate the physical properties of dense cores formed in turbulent, magnetized, parsec-scale clumps of molecular clouds, using three-dimensional numerical simulations that include protostellar outflow feedback. The dense cores are identified in the simulated density data cube through a clumpfind algorithm. We find that the core velocity dispersion does not show any clear dependence on the core size, in contrast to Larson's linewidth-size relation, but consistent with recent observations. In the absence of a magnetic field, the majority of the cores have supersonic velocity dispersions. A moderately-strong magnetic field reduces the dispersion to a subsonic or at most transonic value typically. Most of the cores are out of virial equilibrium, with the external pressure dominating the self-gravity. The implication is that the core evolution is largely controlled by the outflow-driven turbulence. Even an initially-weak magnetic field can retard star formation significantly, because the field is amplified by the outflow-driven turbulence to an equipartition strength, with the distorted field component dominating the uniform one. In contrast, for a moderately-strong field, the uniform component remains dominant. Such a difference in the magnetic structure is evident in our simulated polarization maps of dust thermal emission; it provides a handle on the field strength. Recent polarization measurements show that the field lines in cluster-forming clumps are spatially well-ordered. It is indicative of a moderately-strong, dynamically important, field which, in combination with outflow feedback, can keep the rate of star formation in embedded clusters at the observationally-inferred, relatively-slow rate of several percent per free-fall time.",
  "revisions": [
    {
      "version": "v1",
      "updated": "2011-07-19T02:55:30.000Z"
    }
  ],
  "analyses": {
    "keywords": [
      "dense cores",
      "outflow-driven turbulence",
      "clustered star formation",
      "magnetic clouds",
      "properties"
    ],
    "tags": [
      "journal article"
    ],
    "publication": {
      "doi": "10.1088/0004-637X/740/1/36",
      "journal": "The Astrophysical Journal",
      "year": 2011,
      "month": "Oct",
      "volume": 740,
      "number": 1,
      "pages": 36
    },
    "note": {
      "typesetting": "TeX",
      "pages": 49,
      "language": "en",
      "license": "arXiv",
      "status": "editable",
      "inspire": 919172,
      "adsabs": "2011ApJ...740...36N"
    }
  }
}