The Sloan Digital Sky Survey

Abstract

The Sloan Digital Sky Survey is an ambitious, multi-institutional project to create a huge digital imaging and spectroscopic data bank of 25% of the celestial sphere, approximately 10,000 deg^2 centred on the north galactic polar cap. The photometric atlas will be in 5 specially-chosen colours, covering the pi ster of the Survey area to a limiting magnitude of r~23.1, on 0.4" pixels, resulting in a 1 Tpixel map. This data base will be automatically analysed to catalog the photometric and astrometric properties of 10^8 stellar images, 10^8 galaxies, and 10^6 colour-selected QSO candidates; the galaxy data will in addition include detailed morphological data. The photometric data are used to autonomously and homogeneously select objects for the spectroscopic survey, which will include spectra of 10^6 galaxies, 10^5 QSOs, and 10^5 unusual stars. Although the project was originally motivated by the desire to study Large Scale Structure, we anticipate that these data will impact virtually every field of astronomy, from Earth-crossing asteroids to QSOs at z>6. In particular, the ~12 TByte multi-colour, precision calibrated imaging archive should be a world resource for many decades of the next century.