{
  "id": "astro-ph/9703109",
  "version": "v2",
  "published": "1997-03-18T00:48:48.000Z",
  "updated": "1997-03-18T17:36:17.000Z",
  "title": "Star Formation and Metal Production as a Function of Redshift: The Role of the Multi-Phase ISM",
  "authors": [
    "Marco Spaans",
    "Marcella Carollo"
  ],
  "comment": "18 pages LaTex, Problem with PS figures corrected",
  "doi": "10.1086/310683",
  "categories": [
    "astro-ph"
  ],
  "abstract": "We present models of the cosmological star formation and metal production history of (proto-)galaxies with varying axis ratios. More massive and/or roughly spherical systems reach the threshold-metallicity for a transition to a multi-phase interstellar medium earlier than less massive, more flattened systems. Therefore, more flattened, lower-mass systems start to form stars actively at smaller redshifts. A natural explanation is found in the overall robustness of the interstellar medium against complete expulsion (blow-away) at high total masses, and in the prevention of metal enrichment in the outer regions due to axial outflow along the symmetry axis of a non-spherical proto-galaxy (blow-out). We suggest that the observed predominance of spheroidal systems observed at high redshift, e.g. in the Hubble Deep Field, is due to this effect: At z>2, roundish (proto-)galaxies with total (dark+baryonic) masses of ~10^11 M_o and/or the inner spheroidal cores of similarly massive flattened systems sustain a multi-phase interstellar medium, and therefore a high star-formation rate, whose magnitude depends on the fraction of baryonic matter in the systems. Conversely, the peak at z~1-2 in the observed cosmological metal production rate coincides with the epochs of star formation of lower mass spheroidals, as well as of massive proto-galactic disks.",
  "revisions": [
    {
      "version": "v2",
      "updated": "1997-03-18T17:36:17.000Z"
    }
  ],
  "analyses": {
    "keywords": [
      "star formation",
      "multi-phase ism",
      "metal production rate coincides",
      "massive flattened systems sustain",
      "multi-phase interstellar medium earlier"
    ],
    "tags": [
      "journal article"
    ],
    "note": {
      "typesetting": "LaTeX",
      "pages": 18,
      "language": "en",
      "license": "arXiv",
      "status": "editable",
      "inspire": 460994
    }
  }
}