{
  "id": "astro-ph/9501025",
  "version": "v1",
  "published": "1995-01-09T06:17:51.000Z",
  "updated": "1995-01-09T06:17:51.000Z",
  "title": "INDICATIONS OF DARK MATTER DERIVED FROM LARGE SCALE FLOWS",
  "authors": [
    "Marc Davis",
    "Adi Nusser"
  ],
  "comment": "10 pages, uuencoded compressed postscript file, including 2 figures. also available from ftp://magicbean.berkeley.edu/pub/marc/lsflows.ps.Z",
  "doi": "10.1063/1.48359",
  "categories": [
    "astro-ph"
  ],
  "abstract": "Recent progress in the measurement of relative distances to galaxies has been quite substantial, and catalogs of 3000 galaxies with distances are soon to become available. The peculiar {\\it velocity} field (deviations from Hubble flow) derivable from these catalogs, when compared to the peculiar {\\it gravity} field derived from all sky redshift surveys of galaxies such as the 1.2Jy IRAS survey, leads to a unique and extremely powerful test of the density parameter $\\beta \\equiv \\Omega^{0.6}/b_I$, where $b_I$ is the possible linear bias of the IRAS selected galaxies relative to the mass fluctuations. We review the status of these large scale flow measurements and present a new methodology to describe the two fields by means of an expansion in a set of orthogonalized functions describing a general potential flow to any chosen resolution. The parameters of the flow can be estimated by minimization of the $\\chi^2$ describing the scatter of observed versus predicted linewidths from an inverse Tully-Fisher relation. By this method one can intercompare the gravity and velocity fields coefficient by coefficient, deriving a precise fit for the density parameter and an assessment of the degree of coherence between the fields. The present situation is transitory-- different analyses of the same data are not yielding consistent results. Until this embarassment is untangled, estimates of $\\beta$ should be taken with a large grain of salt.",
  "revisions": [
    {
      "version": "v1",
      "updated": "1995-01-09T06:17:51.000Z"
    }
  ],
  "analyses": {
    "keywords": [
      "dark matter",
      "density parameter",
      "large scale flow measurements",
      "indications",
      "velocity fields coefficient"
    ],
    "tags": [
      "journal article"
    ],
    "note": {
      "typesetting": "TeX",
      "pages": 10,
      "language": "en",
      "license": "arXiv",
      "status": "editable",
      "inspire": 392110
    }
  }
}