Silverman, John D.Green, Paul J.Kim, Dong-WooWilkes, BelindaCameron, Robert A.Morris, DavidDosaj, AnilSmith, ChrisInfante, LeopoldoSmith, Paul S.Jannuzi, Buell T.Mathur, Smita2017-02-132002Silverman, John D., Paul J. Green, Dong-Woo Kim, Belinda J. Wilkes, Robert A. Cameron, David Morris, Anil Dosaj, et al. 2002. “Discovery of a z = 4.93, X-Ray-selected Quasar by the Chandra Multiwavelength Project (ChaMP).” The Astrophysical Journal 569 (1) (April 10): L1–L4. doi:10.1086/340458.0004-637Xhttp://nrs.harvard.edu/urn-3:HUL.InstRepos:30212158We present X-ray and optical observations of CXOMP J213945.0-234655, a high-redshift (z = 4.93) quasar discovered through the Chandra Multiwavelength Project (ChaMP). This object is the most distant X-ray-selected quasar published, with a rest-frame X-ray luminosity of LX = 5.9 × 1044 ergs s-1 (measured in the 0.3-2.5 keV band and corrected for Galactic absorption). CXOMP J213945.0-234655 is a g' dropout object (>26.2), with r' = 22.87 and i' = 21.36. The rest-frame X-ray-to-optical flux ratio is similar to quasars at lower redshifts and slightly X-ray bright relative to z > 4 optically selected quasars observed with Chandra. The ChaMP is beginning to acquire significant numbers of high-redshift quasars to investigate the X-ray luminosity function out to z ~ 5.en-USGalaxies: activeGalaxies: nucleiQuasars: generalQuasars: individual (CXOMP J213945.0 234655)X-rays: generalJournal Article2017-02-1310.1086/340458