Astrophys. J., 729, 141 (2011/March-2)
Think outside the color box: probabilistic target selection and the SDSS-XDQSO quasar targeting catalog.
BOVY J., HENNAWI J.F., HOGG D.W., MYERS A.D., KIRKPATRICK J.A., SCHLEGEL D.J., ROSS N.P., SHELDON E.S., McGREER I.D., SCHNEIDER D.P. and WEAVER B.A.
Abstract (from CDS):
We present the SDSS-XDQSO quasar targeting catalog for efficient flux-based quasar target selection down to the faint limit of the Sloan Digital Sky Survey (SDSS) catalog, even at medium redshifts (2.5 ≲ z ≲ 3) where the stellar contamination is significant. We build models of the distributions of stars and quasars in flux space down to the flux limit by applying the extreme-deconvolution method to estimate the underlying density. We convolve this density with the flux uncertainties when evaluating the probability that an object is a quasar. This approach results in a targeting algorithm that is more principled, more efficient, and faster than other similar methods. We apply the algorithm to derive low-redshift (z < 2.2), medium-redshift (2.2 ≤ z ≤ 3.5), and high-redshift (z>3.5) quasar probabilities for all 160,904,060 point sources with dereddened i-band magnitude between 17.75 and 22.45 mag in the 14,555 deg2 of imaging from SDSS Data Release 8. The catalog can be used to define a uniformly selected and efficient low- or medium-redshift quasar survey, such as that needed for the SDSS-III's Baryon Oscillation Spectroscopic Survey project. We show that the XDQSO technique performs as well as the current best photometric quasar-selection technique at low redshift, and outperforms all other flux-based methods for selecting the medium-redshift quasars of our primary interest. We make code to reproduce the XDQSO quasar target selection publicly available.
catalogs - galaxies: distances and redshifts - methods: statistical - quasars: general - stars: general - stars: statistics
View the references in ADS
To bookmark this query, right click on this link: simbad:2011ApJ...729..141B and select 'bookmark this link' or equivalent in the popup menu