{
  "id": "1101.0813",
  "version": "v1",
  "published": "2011-01-04T21:00:19.000Z",
  "updated": "2011-01-04T21:00:19.000Z",
  "title": "From the molecular-cloud- to the embedded-cluster-mass function with a density threshold for star formation",
  "authors": [
    "Genevieve Parmentier"
  ],
  "comment": "15 pages, 12 figures, accepted to MNRAS",
  "categories": [
    "astro-ph.GA",
    "astro-ph.CO"
  ],
  "abstract": "The mass function of molecular clouds and clumps is shallower than the mass function of young star clusters, gas-embedded and gas-free alike, as their respective mass function indices are $\\beta_0 \\simeq 1.7$ and $\\beta_\\star \\simeq 2$. We demonstrate that such a difference can arise from different mass-radius relations for the embedded-clusters and the molecular clouds (clumps) hosting them. In particular, the formation of star clusters with a constant mean {\\it volume} density in the central regions of molecular clouds of constant mean {\\it surface} density steepens the mass function from clouds to embedded-clusters. This model is observationally supported since the mean surface density of molecular clouds is approximately constant, while there is a growing body of evidence, in both Galactic and extragalactic environments, that efficient star-formation requires a hydrogen molecule number density threshold of $n_{th} \\simeq 10^{4-5}\\,cm^{-3}$. In the framework of the same model, the radius distribution steepens from clouds (clumps) to embedded-clusters, which contributes to explaining observed cluster radius distributions. [Abridged]",
  "revisions": [
    {
      "version": "v1",
      "updated": "2011-01-04T21:00:19.000Z"
    }
  ],
  "analyses": {
    "keywords": [
      "star formation",
      "embedded-cluster-mass function",
      "molecular clouds",
      "hydrogen molecule number density threshold",
      "radius distribution"
    ],
    "tags": [
      "journal article"
    ],
    "publication": {
      "doi": "10.1111/j.1365-2966.2011.18269.x",
      "journal": "Monthly Notices of the Royal Astronomical Society",
      "year": 2011,
      "month": "May",
      "volume": 413,
      "number": 3,
      "pages": 1899
    },
    "note": {
      "typesetting": "TeX",
      "pages": 15,
      "language": "en",
      "license": "arXiv",
      "status": "editable",
      "inspire": 883414,
      "adsabs": "2011MNRAS.413.1899P"
    }
  }
}