The luminosity density of red galaxies

David W. Hogg, Michael Blanton, Iskra Strateva, Neta A. Bahcall, J. Brinkmann, István Csabai, Mamoru Doi, Masataka Fukugita, Greg Hennessy, Željko Ivezić, G. R. Knapp, Don Q. Lamb, Robert Lupton, Jeffrey A. Munn, Robert Nichol, David J. Schlegel, Donald P. Schneider, Donald G. York

    Research output: Contribution to journalArticlepeer-review


    A complete sample of 7.7 × 104 galaxies with five-band imaging and spectroscopic redshifts from the Sloan Digital Sky Survey is used to determine the fraction of the optical luminosity density of the local universe (redshifts 0.02 < z < 0.22) emitted by red galaxies. The distribution in the space of rest-frame color, central surface brightness, and concentration is shown to be highly clustered and bimodal; galaxies fall primarily into one of two distinct classes. One class is red, concentrated, and high in surface brightness; the other is bluer, less concentrated, and lower in central surface brightness. Elliptical and bulge-dominated galaxies preferentially belong to the red class. Even with a very restrictive definition of the red class that includes limits on color, surface brightness, and concentration, the class comprises roughly one-fifth of the number density of galaxies more luminous than 0.05L* and produces two-fifths of the total cosmic galaxy luminosity density at 0.7 μm. The natural interpretation is that a large fraction of the stellar mass density of the local universe is in very old stellar populations.

    Original languageEnglish (US)
    Pages (from-to)646-651
    Number of pages6
    JournalAstronomical Journal
    Issue number2 1760
    StatePublished - Aug 2002


    • Cosmology: observations
    • Galaxies: elliptical and lenticular,cD
    • Galaxies: evolution
    • Galaxies: fundamental parameters
    • Galaxies: stellar content

    ASJC Scopus subject areas

    • Astronomy and Astrophysics
    • Space and Planetary Science


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