High-Redshift Quasars Found in Sloan Digital Sky Survey Commissioning Data

Abstract

We present photometric and spectroscopic observations of 15 high-redshift quasars (z > 3.6) discovered from ~140 deg^2 of five-color (u'g'r'i'z') imaging data taken by the Sloan Digital Sky Survey (SDSS) during its commissioning phase. The quasars are selected by their distinctive colors in SDSS multicolor space. Four of the quasars have redshifts higher than 4.6 (z=4.63, 4.75, 4.90 and 5.00, the latter being the highest redshift quasar yet known). In addition, two previously known z > 4 objects were recovered from the data. The quasars all have i* < 20 and have luminosities comparable to that of 3C273. The spectra of the quasars have similar features (strong, broad emission lines and substantial absorption blueward of the Ly alpha emission line) seen in previously known high-redshift quasars. Although the photometric accuracy and image quality fail to meet the final survey requirements, our success rate for identifying high-redshift quasars (17 quasars from 27 candidates) is much higher than that of previous multicolor surveys. However, the numbers of high-redshift quasars found is in close accord with the number density inferred from previous surveys.

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Affiliated Institutions

• W.M. Keck Observatory US
• University of Chicago US
• University of Pittsburgh US
• Pennsylvania State University US
• Eötvös Loránd University HU
• Carnegie Observatories US
• Princeton University US
• United States Naval Observatory US
• University of Michigan US
• Carnegie Mellon University US
• The Ohio State University US
• Tokyo University of Science JP
• Fermi National Accelerator Laboratory US
• University of Washington US
• Johns Hopkins University US
• Institute for Advanced Study US
• Rochester Institute of Technology US
• The University of Tokyo JP
• Tohoku University JP
• Illinois Institute of Technology US
• National Astronomical Observatory of Japan JP
• Williams (United States) US

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