The Sloan Digital Sky Survey quasar catalog: ninth data release
  We present the Data Release 9 Quasar (DR9Q) catalog from the Baryon
Oscillation Spectroscopic Survey (BOSS) of the Sloan Digital Sky Survey III.
The catalog includes all BOSS objects that were targeted as quasar candidates
during the survey, are spectrocopically confirmed as quasars via visual
inspection, have luminosities Mi[z=2]<-20.5 (in a $\Lambda$CDM cosmology with
H0 = 70 km/s/Mpc, $\Omega_{\rm M}$ = 0.3, and $\Omega_{\Lambda}$ = 0.7) and
either display at least one emission line with full width at half maximum
(FWHM) larger than 500 km/s or, if not, have interesting/complex absorption
features. It includes as well, known quasars (mostly from SDSS-I and II) that
were reobserved by BOSS. This catalog contains 87,822 quasars (78,086 are new
discoveries) detected over 3,275 deg$^{2}$ with robust identification and
redshift measured by a combination of principal component eigenspectra newly
derived from a training set of 8,632 spectra from SDSS-DR7. The number of
quasars with $z>2.15$ (61,931) is ~2.8 times larger than the number of z>2.15
quasars previously known. Redshifts and FWHMs are provided for the strongest
emission lines (CIV, CIII], MgII). The catalog identifies 7,533 broad
absorption line quasars and gives their characteristics. For each object the
catalog presents five-band (u,g,r,i,z) CCD-based photometry with typical
accuracy of 0.03 mag, and information on the morphology and selection method.
The catalog also contains X-ray, ultraviolet, near-infrared, and radio emission
properties of the quasars, when available, from other large-area surveys.
