{
  "id": "astro-ph/9510131",
  "version": "v2",
  "published": "1995-10-25T12:16:31.000Z",
  "updated": "1996-07-25T09:07:03.000Z",
  "title": "Colors, Luminosity Function and Counts of Galaxies",
  "authors": [
    "P. Saracco",
    "G. Chincarini",
    "A. Iovino"
  ],
  "comment": "6 pages, TeX, 9 PostScript figures, to appear in MNRAS",
  "categories": [
    "astro-ph"
  ],
  "abstract": "Standard models for deep galaxy counts are based on luminosity functions (LF) with relatively flat faint end ($\\alpha\\sim-1.0$). Galaxy counts in the B--band exceed the prediction of such models by a factor of 2 to more than 5, forcing the introduction of strong luminosity and/or density evolution. Recently Marzke et al. (1994a) using the CfA redshift survey sample find that the number of galaxies in the range $-16<M_{Zw}<-13$ exceeds the extrapolation of a flat faint end LF by a factor of 2. Here we show that this steep LF substantially contributes to justify the observed blue galaxy counts without invoking strong luminosity and/or density evolution. Furthermore we show that taking into account the variation of the $B-K$ color as a function of the morphological types and assuming a mean value $<B-K><2.5$ for dwarf galaxies, we reproduce well also the observed $K$--band deep galaxy counts. This assumption is supported by the strong correlation we found between $B-K$ color of galaxies and their infrared absolute magnitude: galaxies become bluer with decreasing luminosity.",
  "revisions": [
    {
      "version": "v2",
      "updated": "1996-07-25T09:07:03.000Z"
    }
  ],
  "analyses": {
    "keywords": [
      "luminosity function",
      "band deep galaxy counts",
      "strong luminosity",
      "flat faint end lf",
      "cfa redshift survey sample"
    ],
    "tags": [
      "journal article"
    ],
    "publication": {
      "doi": "10.1093/mnras/283.3.865"
    },
    "note": {
      "typesetting": "TeX",
      "pages": 6,
      "language": "en",
      "license": "arXiv",
      "status": "editable",
      "inspire": 412996
    }
  }
}