We present the Data Release 12 Quasar catalog ( DR12Q ) from the Baryon Oscillation Spectroscopic Survey ( BOSS ) of the Sloan Digital Sky Survey III .
This catalog includes all SDSS-III/BOSS objects that were spectroscopically targeted as quasar candidates during the full survey and that are confirmed as quasars via visual inspection of the spectra , have luminosities M _ { i } [ z = 2 ] < -20.5 ( in a \Lambda CDM cosmology with H _ { 0 } = 70 { km s ^ { -1 } Mpc ^ { -1 } } , \Omega _ { M } = 0.3 , and \Omega _ { \Lambda } = 0.7 ) , and either display at least one emission line with a full width at half maximum ( FWHM ) larger than 500 { km s ^ { -1 } } or , if not , have interesting/complex absorption features .
The catalog also includes previously known quasars ( mostly from SDSS-I and II ) that were reobserved by BOSS .
The catalog contains \ltx @ orig @ numprint 297301 quasars ( \ltx @ orig @ numprint 272026 are new discoveries since the beginning of SDSS-III ) detected over \ltx @ orig @ numprint 9376 { deg ^ { 2 } } with robust identification and redshift measured by a combination of principal component eigenspectra .
The number of quasars with z > 2.15 ( \ltx @ orig @ numprint 184101 , of which \ltx @ orig @ numprint 167742 are new discoveries ) is about an order of magnitude greater than the number of z > 2.15 quasars known prior to BOSS .
Redshifts and FWHMs are provided for the strongest emission lines ( C iv , C iii ] , Mg ii ) .
The catalog identifies \ltx @ orig @ numprint 29580 broad absorption line quasars and lists 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 together with some information on the optical morphology and the selection criteria .
When available , the catalog also provides information on the optical variability of quasars using SDSS and Palomar Transient Factory multi-epoch photometry .
The catalog also contains X-ray , ultraviolet , near-infrared , and radio emission properties of the quasars , when available , from other large-area surveys .
The calibrated digital spectra , covering the wavelength region \ltx @ orig @ numprint 3600 - \ltx @ orig @ numprint 10500 Å at a spectral resolution in the range \ltx @ orig @ numprint 1300 < R < \ltx @ orig @ numprint 2500 , can be retrieved from the SDSS Catalog Archive Server .
We also provide a supplemental list of an additional \ltx @ orig @ numprint 4841 quasars that have been identified serendipitously outside of the superset defined to derive the main quasar catalog .