{
  "id": "0901.2302",
  "version": "v1",
  "published": "2009-01-15T16:27:20.000Z",
  "updated": "2009-01-15T16:27:20.000Z",
  "title": "Stochastic self-enrichment, pre-enrichment, and the formation of globular clusters",
  "authors": [
    "Jeremy Bailin",
    "William E. Harris"
  ],
  "comment": "12 pages, accepted for publication in ApJ",
  "doi": "10.1088/0004-637X/695/2/1082",
  "categories": [
    "astro-ph.GA",
    "astro-ph.CO"
  ],
  "abstract": "We develop a model for stochastic pre-enrichment and self-enrichment in globular clusters (GCs) during their formation process. GCs beginning their formation have an initial metallicity determined by the pre-enrichment of their surrounding protocloud, but can also undergo internal self-enrichment during formation. Stochastic variations in metallicity arise because of the finite numbers of supernova. We construct an analytic formulation of the combined effects of pre-enrichment and self-enrichment and use Monte Carlo models to verify that the model accurately encapsulates the mean metallicity and metallicity spread among real GCs. The predicted metallicity spread due to self-enrichment alone, a robust prediction of the model, is much smaller than the observed spread among real GCs. This result rules out self-enrichment as a significant contributor to the metal content in most GCs, leaving pre-enrichment as the viable alternative. Self-enrichment can, however, be important for clusters with masses well above 10^6 Msun, which are massive enough to hold in a significant fraction of their SN ejecta even without any external pressure confinement. This transition point corresponds well to the mass at which a mass-metallicity relationship (\"blue tilt\") appears in the metal-poor cluster sequence in many large galaxies. We therefore suggest that self-enrichment is the primary driver for the mass-metallicity relation. Other predictions from our model are that the cluster-to-cluster metallicity spread decreases amongst the highest mass clusters; and that the red GC sequence should also display a more modest mass-metallicity trend if it can be traced to similarly high mass.",
  "revisions": [
    {
      "version": "v1",
      "updated": "2009-01-15T16:27:20.000Z"
    }
  ],
  "analyses": {
    "keywords": [
      "globular clusters",
      "pre-enrichment",
      "stochastic self-enrichment",
      "cluster-to-cluster metallicity spread decreases",
      "real gcs"
    ],
    "tags": [
      "journal article"
    ],
    "publication": {
      "journal": "The Astrophysical Journal",
      "year": 2009,
      "month": "Apr",
      "volume": 695,
      "number": 2,
      "pages": 1082
    },
    "note": {
      "typesetting": "TeX",
      "pages": 12,
      "language": "en",
      "license": "arXiv",
      "status": "editable",
      "inspire": 811110,
      "adsabs": "2009ApJ...695.1082B"
    }
  }
}