A simple likelihood method for quasar target selection

Jessica A. Kirkpatrick, David J. Schlegel, Nicholas P. Ross, Adam D. Myers, Joseph F. Hennawi, Erin S. Sheldon, Donald P. Schneider, Benjamin A. Weaver

Research output: Contribution to journalArticlepeer-review

53 Scopus citations


We present a new method for quasar target selection using photometric fluxes and a Bayesian probabilistic approach. For our purposes, we target quasars using Sloan Digital Sky Survey (SDSS) photometry to a magnitude limit of g = 22. The efficiency and completeness of this technique are measured using the Baryon Oscillation Spectroscopic Survey (BOSS) data taken in 2010. This technique was used for the uniformly selected (CORE) sample of targets in BOSS year-one spectroscopy to be realized in the ninth SDSS data release. When targeting at a density of 40 objectsdeg-2 (the BOSS quasar targeting density), the efficiency of this technique in recovering z > 2.2 quasars is 40%. The completeness compared to all quasars identified in BOSS data is 65%. This paper also describes possible extensions and improvements for this technique.

Original languageEnglish (US)
Article number125
JournalAstrophysical Journal
Issue number2
StatePublished - Dec 20 2011

All Science Journal Classification (ASJC) codes

  • Astronomy and Astrophysics
  • Space and Planetary Science


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