Description
The Sloan Digital Sky Survey (SDSS) has observed more than a quarter of the sky over eight years of operations, obtaining multicolor photometry and spectroscopy for ~ 1 million of galaxies, and the GALEX survey is the ultraviolet counterpart of the SDSS. A catalog of photometric redshifts (evaluated using optical and ultraviolet photometry) for ~150000 candidate quasars with magnitude r < 20.7, extracted from the SDSS DR7 dataset (D'Abrusco et al, 2009) and with GALEX counterparts, is provided here. The photometric redshifts and the uncertainty of the estimates for each source have been calculated using the Weak Gated Expert (WGE) method. The WGE (Laurino et al., submitted to MNRAS) is based on the exploitation of the spectroscopic redshifts for a subset of photometric sources and derives photometric redshifts through a combination of data mining techniques. This method can be applied to different classes of extragalactic sources and is scalable. A set of observational parameters used for the evaluation of photometric redshifts, the estimated photometric redshifts values and some of the most common observational parameters retrieved from the SDSS and GALEX databases have been included in the catalog for the sake of simplicity.
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