@article{c96a07cdf55d4b4fa4fe4fb4cf60e37d,
title = "Discovery of A Z P 4.93, x-ray–selected quasar by the chandra multiwavelength project (ChaMP)",
abstract = "We present X-ray and optical observations of CXOMP J213945.0234655, a high-redshift (z p 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 L X p 5.9 # 10 44 ergs s1 (measured in the 0.3–2.5 keV band and corrected for Galactic absorption). CXOMP J213945.0234655 is a g dropout object (126.2), with r p 22.87 and i p 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 1 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.",
keywords = "Galaxies: active, Galaxies: nuclei, Quasars: general, Quasars: individual (CXOMP J213945.0234655), X-rays: general",
author = "Silverman, {John D.} and Green, {Paul J.} and Kim, {Dong Woo} and Wilkes, {Belinda J.} and Cameron, {Robert A.} and David Morris and Anil Dosaj and Chris Smith and Leopoldo Infante and Smith, {Paul S.} and Jannuzi, {Buell T.} and Smita Mathur",
note = "Funding Information: 1Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138; jds@head-cfa.harvard.edu. 2Astronomy Department, University of Virginia, P.O. Box 3818, Charlottesville, VA 22903-0818. 3Visiting Astronomer, Cerro Tololo Inter-American Observatory, National Optical Astronomy Observatory, which is operated by the Association of Universities for Research in Astronomy (AURA), Inc., under cooperative agreement with the National Science Foundation. 4Cerro Tololo Inter-American Observatory, National Optical Astronomy Observatory, Casilla 603, La Serena, Chile. 5 Departamento de Astronom{\'i}a y Astrof{\'i}sica, P. Universidad Cat{\'o}lica, Cas-illa 306, Santiago, Chile. 6Visiting Astronomer, ESO New Technology Telescope. 7Steward Observatory, University of Arizona, 933 North Cherry Avenue, Tucson, AZ 85721. 8National Optical Astronomy Observatory, P.O. Box 26732, Tucson, AZ 85726-6732. 9Astronomy Department, Ohio State University, 140 West 18th Avenue, Columbus, OH 43210. Funding Information: We gratefully acknowledge support for this Chandra archival research from NASA grant AR1-2003X. R. A. C., A. D., P. J. G., D.-W. K., D. M., and B. J. W. also acknowledge support through NASA contract NAS8-39073 (CXC). L. I. is grateful to “Proyecto Puente PUC” and the Center for Astrophysics FONDAP for partial financial support. B. T. J. acknowledges research support from the National Science Foundation, through their cooperative agreement with AURA, Inc., for the operation of the NOAO. We are thankful to Sam Barden and Tom Ingerson (NOAO) for building and commissioning Hydra/ CTIO. We greatly appreciate the observing support from Knut Olsen (NOAO) and constructive comments by Harvey Tan-anbaum and Dan Harris. Publisher Copyright: {\textcopyright} 2002. The American Astronomical Society. All rights reserved",
year = "2002",
month = mar,
day = "20",
doi = "10.1086/340144",
language = "English (US)",
volume = "569",
pages = "L1--L4",
journal = "Astrophysical Journal Letters",
issn = "2041-8205",
publisher = "IOP Publishing Ltd.",
number = "1",
}