Photometric Catalogue of Quasars and Other Point Sources in the Sloan Digital Sky Survey

Abstract
We present a catalogue of about 8.6 million unresolved photometric detections in the Sloan Digital Sky Survey Seventh Data Release classifying them into stars, galaxies and quasars using a machine learning classifier trained on a subset of spectroscopically confirmed objects. Our catalogue consists of 4,046,117 quasars, 3,922,329 stars and 656,456 unresolved galaxies from 17th to 24th magnitude in the SDSS -band. This has enabled us to identify 4 times more quasar candidates than the largest photometric quasar catalogue presently available. The quasar surface density in our catalogue is expected to have a completeness of more than 90 per cent up to 24th magnitude within the colour window we have studied.
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