THE SEVENTH DATA RELEASE OF THE SLOAN DIGITAL SKY SURVEY

Abstract

This paper describes the Seventh Data Release of the Sloan Digital Sky Survey (SDSS), marking the completion of the original goals of the SDSS and the end of the phase known as SDSS-II. It includes 11,663 deg² of imaging data, with most of the ~2000 deg² increment over the previous data release lying in regions of low Galactic latitude. The catalog contains five-band photometry for 357 million distinct objects. The survey also includes repeat photometry on a 120° long, 2fdg5 wide stripe along the celestial equator in the Southern Galactic Cap, with some regions covered by as many as 90 individual imaging runs. We include a co-addition of the best of these data, going roughly 2 mag fainter than the main survey over 250 deg². The survey has completed spectroscopy over 9380 deg²; the spectroscopy is now complete over a large contiguous area of the Northern Galactic Cap, closing the gap that was present in previous data releases. There are over 1.6 million spectra in total, including 930,000 galaxies, 120,000 quasars, and 460,000 stars. The data release includes improved stellar photometry at low Galactic latitude. The astrometry has all been recalibrated with the second version of the USNO CCD Astrograph Catalog, reducing the rms statistical errors at the bright end to 45 milliarcseconds per coordinate. We further quantify a systematic error in bright galaxy photometry due to poor sky determination; this problem is less severe than previously reported for the majority of galaxies. Finally, we describe a series of improvements to the spectroscopic reductions, including better flat fielding and improved wavelength calibration at the blue end, better processing of objects with extremely strong narrow emission lines, and an improved determination of stellar metallicities.

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Affiliated Institutions

• Crow Canyon Archaeological Center US
• Space Telescope Science Institute US
• California Institute of Technology US
• Kavli Institute for Particle Astrophysics and Cosmology US
• University College London GB
• Monterey Institute for Research in Astronomy US
• Lowell Observatory US
• San Diego State University US
• Gemini North Observatory US
• Fermi National Accelerator Laboratory US
• University of Pennsylvania US
• York University CA
• The University of Texas at Austin US
• Michigan State University US
• University of Illinois Urbana-Champaign US
• Deleted Institution
• University of Cape Town ZA
• Institute of Space Sciences ES
• Herzberg Institute of Astrophysics CA
• New Mexico State University US
• Columbia University US
• Institute for Advanced Study US
• Max Planck Institute for Astronomy DE
• Heliophysics US
• Centre for Astrophysics of the University of Porto PT
• University of Wyoming US
• Seoul National University KR
• University of Cambridge GB
• United States Naval Research Laboratory US
• New Mexico Institute of Mining and Technology US
• American Museum of Natural History US
• United States Naval Observatory US
• Joint Institute for Nuclear Astrophysics US
• Case Western Reserve University US
• Infrared Processing and Analysis Center US
• Leiden University NL
• Kavli Institute for the Physics and Mathematics of the Universe JP
• University of Maryland, College Park US
• University of Chicago US
• Eötvös Loránd University HU
• Princeton University US
• University of Michigan US
• The Ohio State University US
• Vanderbilt University US
• New York University US
• University of Washington US
• Johns Hopkins University US
• University of Portsmouth GB
• South African Radio Astronomy Observatory ZA
• Rutgers, The State University of New Jersey US
• The University of Tokyo JP
• Tohoku University JP
• Wayne State University US
• University of Warwick GB
• National Astronomical Observatory of Japan JP
• Heidelberg University DE
• Université Bourgogne Franche-Comté FR

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