A Full Year's Chandra Exposure on SDSS Quasars from the Chandra Multiwavelength Project Export

@article{citeulike:3214308, abstract = {We study the spectral energy distributions and evolution of a large sample of optically selected quasars from the Sloan Digital Sky Survey (SDSS) that were observed in 323 Chandra images analyzed by the Chandra Multiwavelength Project (ChaMP). Our highest-confidence matched sample includes 1135 X-ray detected quasars in the redshift range 0.2\<z\<5.4, representing some 36Msec of effective exposure. Spectroscopic redshifts are available for about 1/3 of the detected sample; elsewhere, redshifts are estimated photometrically. With 56 z\>3 QSOs detected, we find no evidence for evolution out to z\~{}5 for either the X-ray photon index Gamma or for the ratio of optical/UV to X-ray flux alpha\_ox. About 10\% of detected QSOs are obscured (Nh\>1E22), but the fraction might reach \~{}1/3 if most non-detections are absorbed. We confirm a significant correlation between alpha\_ox and optical luminosity, but it flattens or disappears for fainter AGN alone. Gamma hardens significantly both towards higher X-ray luminosity, and for relatively X-ray loud quasars. These trends may represent a relative increase in non-thermal X-ray emission, and our findings thereby strengthen analogies between Galactic black hole binaries and AGN.}, archivePrefix = {arXiv}, author = {Green, Paul J. and Aldcroft, T. L. and Richards, G. T. and Barkhouse, W. A. and Constantin, A. and Haggard, D. and Karovska, M. and -W and Kim, M. and Vikhlinin, A. and Mossman, A. and Silverman, J. D. and Anderson, S. F. and Kashyap, V. and Wilkes, B. J. and Tananbaum, H.}, citeulike-article-id = {3214308}, citeulike-linkout-0 = {http://arxiv.org/abs/0809.1058}, citeulike-linkout-1 = {http://arxiv.org/pdf/0809.1058}, day = {5}, eprint = {0809.1058}, keywords = {agn, archive, champ, chandra}, month = {Sep}, posted-at = {2008-09-11 02:53:17}, priority = {2}, title = {A Full Year's Chandra Exposure on SDSS Quasars from the Chandra Multiwavelength Project}, url = {http://arxiv.org/abs/0809.1058}, year = {2008} }

TY - JOUR ID - citeulike:3214308 L3 - citeulike-article-id:3214308 N2 - We study the spectral energy distributions and evolution of a large sample of optically selected quasars from the Sloan Digital Sky Survey (SDSS) that were observed in 323 Chandra images analyzed by the Chandra Multiwavelength Project (ChaMP). Our highest-confidence matched sample includes 1135 X-ray detected quasars in the redshift range 0.2<z<5.4, representing some 36Msec of effective exposure. Spectroscopic redshifts are available for about 1/3 of the detected sample; elsewhere, redshifts are estimated photometrically. With 56 z>3 QSOs detected, we find no evidence for evolution out to z~5 for either the X-ray photon index Gamma or for the ratio of optical/UV to X-ray flux alpha_ox. About 10% of detected QSOs are obscured (Nh>1E22), but the fraction might reach ~1/3 if most non-detections are absorbed. We confirm a significant correlation between alpha_ox and optical luminosity, but it flattens or disappears for fainter AGN alone. Gamma hardens significantly both towards higher X-ray luminosity, and for relatively X-ray loud quasars. These trends may represent a relative increase in non-thermal X-ray emission, and our findings thereby strengthen analogies between Galactic black hole binaries and AGN. TI - A Full Year's Chandra Exposure on SDSS Quasars from the Chandra Multiwavelength Project KW - agn KW - archive KW - champ KW - chandra AU - Green, Paul AU - Aldcroft, TL AU - Richards, GT AU - Barkhouse, WA AU - Constantin, A AU - Haggard, D AU - Karovska, M AU - -W AU - Kim, M AU - Vikhlinin, A AU - Mossman, A AU - Silverman, JD AU - Anderson, SF AU - Kashyap, V AU - Wilkes, BJ AU - Tananbaum, H PY - 2008/Sep/05/ UR - http://arxiv.org/abs/0809.1058 ER -