  We present the third edition of the Sloan Digital Sky Survey (SDSS) Quasar
Catalog. The catalog consists of the 46,420 objects in the SDSS Third Data
Release that have luminosities larger than M_i = -22 (in a cosmology with H_0 =
70 km/s/Mpc, Omega_M = 0.3, and Omega_Lambda = 0.7), have at least one emission
line with FWHM larger than 1000 km/s or are unambiguously broad absorption line
quasars, are fainter than i = 15.0, and have highly reliable redshifts. The
area covered by the catalog is 4188 sq. deg. The quasar redshifts range from
0.08 to 5.41, with a median value of 1.47; the high-redshift sample includes
520 quasars at redshifts greater than four, of which 17 are at redshifts
greater than five. For each object the catalog presents positions accurate to
better than 0.2 arcsec. rms per coordinate, five-band (ugriz) CCD-based
photometry with typical accuracy of 0.03 mag, and information on the morphology
and selection method. The catalog also contains radio, near-infrared, and X-ray
emission properties of the quasars, when available, from other large-area
surveys. The calibrated digital spectra cover the wavelength region 3800--9200A
at a spectral resolution about 2000; the spectra can be retrieved from the
public database using the information provided in the catalog. A total of
44,221 objects in the catalog were discovered by the SDSS; 28,400 of the SDSS
discoveries are reported here for the first time.
