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Type II quasars are the long-sought luminous analogs of type II (narrowemission line) Seyfert galaxies, suggested by unification models of activegalactic nuclei (AGN) and postulated to account for an appreciable fraction ofthe cosmic hard X-ray background. We present a sample of 291 type II AGN atredshifts 0.3<Z<0.83 from the spectroscopic data of the Sloan Digital SkySurvey. These objects have narrow (FWHM<2000 km/s), high equivalent widthemission lines with high-ionization line ratios. We describe the selectionprocedure and discuss the optical properties of the sample. About 50% of theobjects have [OIII] \lambda_air 5007 line luminosities in the range 3\times10^8-10^10 L_Sun, comparable to those of luminous (-27<M_B<-23) quasars; this,along with other evidence, suggests that the objects in the luminous subsampleare type II quasars.

Candidate Type II Quasars from the Sloan Digital Sky Survey. I. Selection and Optical Properties of a Sample at 0.3<Z<0.83