The discovery of five quasars at z>4 using the Second Palomar Sky Survey

J. D. Kennefick, R. R. De Carvalho, S. G. Djorgovski, M. M. Wilber, Eric Dickson, N. Weir, U. Fayyad, J. Roden

    Research output: Contribution to journalArticle

    Abstract

    We are conducting a survey to identity z>4 quasars using a digital version of the Second Palomar Sky Survey. The plates are taken in the photographic JFN bands and calibrated to the Gunn-Thuan gri system, making these data suitable for a multicolor search for quasars in the redshift range of 4.0≲z≲4.8. A new software package, SKICAT, was developed to perform automatic reduction of these scans into object catalogs, to classify the objects as stars or galaxies to faint levels objectively using a machine learning decision tree method, and to allow for easy manipulation of the final catalogs. Here we report on the initial results from this survey. We have selected high-redshift quasar candidates from 14 fields with a total area covered of ∼560 deg2 over the magnitude range 16.5≤mr≤19.6. Follow-up work is now well underway, and is complete for several fields. Here we present a preliminary description of the survey as well as spectroscopy, coordinates, and finding charts for our first five z>4 quasars.

    Original languageEnglish (US)
    Pages (from-to)78-86
    Number of pages9
    JournalAstronomical Journal
    Volume110
    Issue number1
    StatePublished - Jul 1995

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    quasars
    catalogs
    machine learning
    charts
    manipulators
    spectroscopy
    galaxies
    computer programs
    software
    conduction
    stars

    ASJC Scopus subject areas

    • Space and Planetary Science
    • Astronomy and Astrophysics

    Cite this

    Kennefick, J. D., De Carvalho, R. R., Djorgovski, S. G., Wilber, M. M., Dickson, E., Weir, N., ... Roden, J. (1995). The discovery of five quasars at z>4 using the Second Palomar Sky Survey. Astronomical Journal, 110(1), 78-86.

    The discovery of five quasars at z>4 using the Second Palomar Sky Survey. / Kennefick, J. D.; De Carvalho, R. R.; Djorgovski, S. G.; Wilber, M. M.; Dickson, Eric; Weir, N.; Fayyad, U.; Roden, J.

    In: Astronomical Journal, Vol. 110, No. 1, 07.1995, p. 78-86.

    Research output: Contribution to journalArticle

    Kennefick, JD, De Carvalho, RR, Djorgovski, SG, Wilber, MM, Dickson, E, Weir, N, Fayyad, U & Roden, J 1995, 'The discovery of five quasars at z>4 using the Second Palomar Sky Survey', Astronomical Journal, vol. 110, no. 1, pp. 78-86.
    Kennefick JD, De Carvalho RR, Djorgovski SG, Wilber MM, Dickson E, Weir N et al. The discovery of five quasars at z>4 using the Second Palomar Sky Survey. Astronomical Journal. 1995 Jul;110(1):78-86.
    Kennefick, J. D. ; De Carvalho, R. R. ; Djorgovski, S. G. ; Wilber, M. M. ; Dickson, Eric ; Weir, N. ; Fayyad, U. ; Roden, J. / The discovery of five quasars at z>4 using the Second Palomar Sky Survey. In: Astronomical Journal. 1995 ; Vol. 110, No. 1. pp. 78-86.
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