A dataset provided by the European Space Agency

Name: An X-ray Study of the Most Distant Quasars from the Sloan Digital Sky Survey
Published: 2003-03-30T00:00:00Z

Proposal ID	003654
Title	An X-ray Study of the Most Distant Quasars from the Sloan Digital Sky Survey
Download Data Associated to the proposal	https://nxsa.esac.esa.int/nxsa-sl/servlet/data-action-aio?obsno=0036540101
DOI	https://doi.org/10.5270/esa-zyq469l
Principal Investigator, PI	Prof William Brandt
Abstract	We propose to begin a systematic X-ray study of the highest redshift quasars found by the Sloan Digital Sky Survey (SDSS). Here we propose observationsof the three highest redshift quasars found by the SDSS to date (z=4.9-5.0). SDSS quasars are selected in a uniform and highly effective manner, and they are ideal for defining the basic X-ray properties of the youngest known quasars. The observations will constrain the X-ray luminosity function of the highest redshift quasars and will identify any objects bright enough for X-ray spectroscopy. We intend to expand this investigation as additional SDSS quasars are found, with our ultimate goals being to determine the evolution of quasar X-ray power sources and environments.
Publications	The XMM-Newton Needles in the Haystack Survey: the local X-ray luminosity function of normal. galaxies \|Georgantopoulos, I., Georgakakis, A., \| MNRAS \| 360-782 \| 2005 \| 2005MNRAS.360..782G \| http://ui.adsabs.harvard.edu/#abs/2005MNRAS.360..782G The XMM-Newton serendipitous survey. V. The Second XMM-Newton serendipitous source catalogue \|Watson, M. G., Schroder, A. C., et al. \| A&A \| 493-339 \| 2009 \| 2009A&A...493..339W \| http://ui.adsabs.harvard.edu/#abs/2009A&A...493..339W An Extremely Luminous Panchromatic Outburst from the Nucleus of a Distant Galaxy \|Levan, A. J., Tanvir, N. R., et al. \| Sci \| 333-199 \| 2011 \| 2011Sci...333..199L \| http://ui.adsabs.harvard.edu/#abs/2011Sci...333..199L The XMM-Newton Wide Angle Survey (XWAS): the X-ray spectrum of type-1 AGN \|Mateos, S., Carrera, F. J., et al. \| A&A \| 510-35 \| 2010 \| 2010A&A...510A..35M \| http://ui.adsabs.harvard.edu/#abs/2010A&A...510A..35M Average Fe Kalpha emission from distant AGN \|Corral, A., Page, M. J., et al. \| A&A \| 492-71 \| 2008 \| 2008A&A...492...71C \| http://ui.adsabs.harvard.edu/#abs/2008A&A...492...71C Studying the X-ray/UV Variability of Active Galactic Nuclei with data from Swift and XMM archives \|Turriziani, Sara, \| JPhCS \| 280-12005 \| 2011 \| 2011JPhCS.280a2005T \| http://ui.adsabs.harvard.edu/#abs/2011JPhCS.280a2005T New constraints on the X-ray spectral properties of type 1 active galactic nuclei \|Scott, A. E., Stewart, G. C., et al. \| MNRAS \| 417-992 \| 2011 \| 2011MNRAS.417..992S \| http://ui.adsabs.harvard.edu/#abs/2011MNRAS.417..992S X-ray absorption in distant type II QSOs \|Krumpe, M., Lamer, G., et al. \| A&A \| 483-415 \| 2008 \| 2008A&A...483..415K \| http://ui.adsabs.harvard.edu/#abs/2008A&A...483..415K The x-ray luminous galaxy cluster population at 0.9 < z &lsim; 1.6 as revealed by the XMM-Newton Distant Cluster Project \|Fassbender, R., Bohringer, H., et al. \| NJPh \| 13-125014 \| 2011 \| 2011NJPh...13l5014F \| http://ui.adsabs.harvard.edu/#abs/2011NJPh...13l5014F Statistical evaluation of the flux cross-calibration of the XMM-Newton EPIC cameras \|Mateos, S., Saxton, R. D., et al. \| A&A \| 496-879 \| 2009 \| 2009A&A...496..879M \| http://ui.adsabs.harvard.edu/#abs/2009A&A...496..879M First simultaneous optical/near-infrared imaging of an X-ray selected, high-redshift cluster of galaxies with GROND. The galaxy population of XMMU J0338.7 + 0030 at z = 1.1 \|Pierini, D., Suhada, R., et al. \| A&A \| 540-45 \| 2012 \| 2012A&A...540A..45P \| http://ui.adsabs.harvard.edu/#abs/2012A&A...540A..45P The XMM Cluster Survey: optical analysis methodology and the first data release \|Mehrtens, Nicola, Romer, A. Kathy, et al. \| MNRAS \| 423-1024 \| 2012 \| 2012MNRAS.423.1024M \| http://ui.adsabs.harvard.edu/#abs/2012MNRAS.423.1024M The 2XMMi/SDSS Galaxy Cluster Survey. I. The first cluster sample and X-ray luminosity-temperature relation \|Takey, A., Schwope, A., \| A&A \| 534-120 \| 2011 \| 2011A&A...534A.120T \| http://ui.adsabs.harvard.edu/#abs/2011A&A...534A.120T XMM-Newton data processing for faint diffuse emission. Proton flares, exposure maps and report on EPIC MOS1 bright CCDs contamination \|Pradas, J., Kerp, J., \| A&A \| 443-721 \| 2005 \| 2005A&A...443..721P \| http://ui.adsabs.harvard.edu/#abs/2005A&A...443..721P XMM-Newton and Chandra measurements of the AGN intrinsic absorption: dependence on luminosity and redshift \|Akylas, A., Georgantopoulos, I., et al. \| A&A \| 459-693 \| 2006 \| 2006A&A...459..693A \| http://ui.adsabs.harvard.edu/#abs/2006A&A...459..693A XMM-Newton Observations of Optically Selected Sloan Digital Sky Survey Clusters \|Plionis, M., Basilakos, S., et al. \| ApJ \| 622-17 \| 2005 \| 2005ApJ...622L..17P \| http://ui.adsabs.harvard.edu/#abs/2005ApJ...622L..17P Are Optically Selected Quasars Universally X-Ray Luminous? X-Ray-UV Relations in Sloan Digital Sky Survey Quasars \|Gibson, Robert R., Brandt, W. N., \| ApJ \| 685-773 \| 2008 \| 2008ApJ...685..773G \| http://ui.adsabs.harvard.edu/#abs/2008ApJ...685..773G Chandra and XMM-Newton Observations of the First Quasars: X-Rays from the Age of Cosmic Enlightenment \|Vignali, C., Brandt, W. N., et al. \| AJ \| 125-2876 \| 2003 \| 2003AJ....125.2876V \| http://ui.adsabs.harvard.edu/#abs/2003AJ....125.2876V A serendipitous XMM survey of the SDSS: the evolution of the colour-magnitude diagram of X-ray AGN from z= 0.8 to 0.1 \|Georgakakis, Antonis, Nandra, K., \| MNRAS \| 414-992 \| 2011 \| 2011MNRAS.414..992G \| http://ui.adsabs.harvard.edu/#abs/2011MNRAS.414..992G An All-Sky Atlas of Radio/X-ray Associations \|Flesch, E., \| PASA \| 27-283 \| 2010 \| 2010PASA...27..283F \| http://ui.adsabs.harvard.edu/#abs/2010PASA...27..283F Discovery of the X-ray selected galaxy cluster XMMU J0338.8+0021 at z = 1.49. Indications of a young system with a brightest galaxy in formation \|Nastasi, A., Fassbender, R., et al. \| A&A \| 532-6 \| 2011 \| 2011A&A...532L...6N \| http://ui.adsabs.harvard.edu/#abs/2011A&A...532L...6N Red active galactic nuclei in XMM-Newton/Sloan Digital Sky Survey fields \|Georgakakis, A. E., Georgantopoulos, I., \| MNRAS \| 366-171 \| 2006 \| 2006MNRAS.366..171G \| http://ui.adsabs.harvard.edu/#abs/2006MNRAS.366..171G The XMM Cluster Survey: X-ray analysis methodology \|Lloyd-Davies, E. J., Romer, A. Kathy, et al. \| MNRAS \| 418-14 \| 2011 \| 2011MNRAS.418...14L \| http://ui.adsabs.harvard.edu/#abs/2011MNRAS.418...14L Exospheric solar wind charge exchange as seen by XMM-Newton \|Carter, J. A., Semba, S., \| AN \| 333-313 \| 2012 \| 2012AN....333..313C \| http://ui.adsabs.harvard.edu/#abs/2012AN....333..313C Detectability of low-energy X-ray spectral components in type 1 active galactic nuclei \|Scott, A. E., Stewart, G. C., \| MNRAS \| 423-2633 \| 2012 \| 2012MNRAS.423.2633S \| http://ui.adsabs.harvard.edu/#abs/2012MNRAS.423.2633S The cosmological analysis of X-ray cluster surveys - II. Application of the CR-HR method to the XMM archive \|Clerc, N., Sadibekova, T., et al. \| MNRAS \| 423-3561 \| 2012 \| 2012MNRAS.423.3561C \| http://ui.adsabs.harvard.edu/#abs/2012MNRAS.423.3561C Variability and the X-ray/UV ratio of active galactic nuclei \|Vagnetti, F., Turriziani, S., et al. \| A&A \| 519-17 \| 2010 \| 2010A&A...519A..17V \| http://ui.adsabs.harvard.edu/#abs/2010A&A...519A..17V The XMM-Newton serendipitous ultraviolet source survey catalogue \|Page, M. J., Brindle, C., et al. \| MNRAS \| 426-903 \| 2012 \| 2012MNRAS.426..903P \| http://ui.adsabs.harvard.edu/#abs/2012MNRAS.426..903P Ensemble X-ray variability of active galactic nuclei from serendipitous source catalogues \|Vagnetti, F., Turriziani, S., \| A&A \| 536-84 \| 2011 \| 2011A&A...536A..84V \| http://ui.adsabs.harvard.edu/#abs/2011A&A...536A..84V AGN Triggering in the Infall Regions of Distant X-Ray Luminous Galaxy Clusters at 0.9 < z <virgul 1.6 \|Fassbender, R., Suhada, R., \| AdAst2012E \| 2012-138380 \| 2012 \| 2012AdAst2012E..32F \| http://ui.adsabs.harvard.edu/#abs/2012AdAst2012E..32F Cross-correlation of the 2XMMi catalogue with Data Release 7 of the Sloan Digital Sky Survey \|Pineau, F.-X., Motch, C., et al. \| A&A \| 527-126 \| 2011 \| 2011A&A...527A.126P \| http://ui.adsabs.harvard.edu/#abs/2011A&A...527A.126P Exploring X-ray and radio emission of type 1 AGN up to z virgul 2.3 \|Ballo, L., Heras, F. J. H., et al. \| A&A \| 545-66 \| 2012 \| 2012A&A...545A..66B \| http://ui.adsabs.harvard.edu/#abs/2012A&A...545A..66B X-ray bright optically inactive galaxies in XMM-Newton/Sloan Digital Sky Survey fields: more diluted than absorbed? \|Georgantopoulos, I., Georgakakis, A., \| MNRAS \| 358-131 \| 2005 \| 2005MNRAS.358..131G \| http://ui.adsabs.harvard.edu/#abs/2005MNRAS.358..131G High spectral resolution X-ray observations of AGN \|Kaastra, J. S., \| AN \| 329-162 \| 2008 \| 2008AN....329..162K \| http://ui.adsabs.harvard.edu/#abs/2008AN....329..162K The XMM-Newton Wide Angle Survey (XWAS) \|Esquej, P., Page, M., et al. \| A&A \| 557-123 \| 2013 \| 2013A&A...557A.123E \| http://ui.adsabs.harvard.edu/#abs/2013A&A...557A.123E Finding rare AGN: XMM-Newton and Chandra observations of SDSS Stripe 82 \|LaMassa, Stephanie M., Urry, C. Megan, et al. \| MNRAS \| 436-3581 \| 2013 \| 2013MNRAS.436.3581L \| http://ui.adsabs.harvard.edu/#abs/2013MNRAS.436.3581L Automatic Classification of Time-variable X-Ray Sources \|Lo, Kitty K., Farrell, Sean, et al. \| ApJ \| 786-20 \| 2014 \| 2014ApJ...786...20L \| http://ui.adsabs.harvard.edu/#abs/2014ApJ...786...20L Serendipitous UV source catalogues for 10 years of XMM and 5 years of Swift \|Yershov, V. N., \| Ap&SS \| 354-97 \| 2014 \| 2014Ap&SS.354...97Y \| http://ui.adsabs.harvard.edu/#abs/2014Ap&SS.354...97Y Obscuration-dependent Evolution of Active Galactic Nuclei \|Buchner, Johannes, Georgakakis, Antonis, et al. \| ApJ \| 802-89 \| 2015 \| 2015ApJ...802...89B \| http://ui.adsabs.harvard.edu/#abs/2015ApJ...802...89B Non-thermal cosmic backgrounds from blazars: the contribution to the CMB, X-ray and gamma-ray backgrounds \|Giommi, P., Colafrancesco, S., et al. \| A&A \| 445-843 \| 2006 \| 2006A&A...445..843G \| http://ui.adsabs.harvard.edu/#abs/2006A&A...445..843G Sunyaev-Zel.dovich effect or not? Detecting the main foreground effect of most galaxy clusters \|Xiao, Weike, Chen, Chen, et al. \| MNRAS \| 432-41 \| 2013 \| 2013MNRAS.432L..41X \| http://ui.adsabs.harvard.edu/#abs/2013MNRAS.432L..41X Do the spectral energy distributions of type 1 active galactic nuclei show diversity? \|Scott, A. E., Stewart, G. C., \| MNRAS \| 438-2253 \| 2014 \| 2014MNRAS.438.2253S \| http://ui.adsabs.harvard.edu/#abs/2014MNRAS.438.2253S A survey of stellar X-ray flares from the XMM-Newton serendipitous source catalogue: HIPPARCOS-Tycho cool stars \|Pye, J. P., Rosen, S., et al. \| A&A \| 581-28 \| 2015 \| 2015A&A...581A..28P \| http://ui.adsabs.harvard.edu/#abs/2015A&A...581A..28P XMM-Newton publication statistics \|Ness, J.-U., Parmar, A. N., et al. \| AN \| 335-210 \| 2014 \| 2014AN....335..210N \| http://ui.adsabs.harvard.edu/#abs/2014AN....335..210N The Tight Relation between X-Ray and Ultraviolet Luminosity of Quasars \|Lusso, E., Risaliti, G., \| ApJ \| 819-154 \| 2016 \| 2016ApJ...819..154L \| http://ui.adsabs.harvard.edu/#abs/2016ApJ...819..154L SPIDERS: the spectroscopic follow-up of X-ray selected clusters of galaxies in SDSS-IV \|Clerc, N., Merloni, A., et al. \| MNRAS \| 463-4490 \| 2016 \| 2016MNRAS.463.4490C \| http://ui.adsabs.harvard.edu/#abs/2016MNRAS.463.4490C The Million Optical - Radio/X-ray Associations (MORX) Catalogue \|Flesch, Eric W., \| PASA \| 33-52 \| 2016 \| 2016PASA...33...52F \| http://ui.adsabs.harvard.edu/#abs/2016PASA...33...52F Studying Cosmic Evolution with the XMM-Newton Distant Cluster Project: X-ray Luminous Galaxy Clusters at z>virgul1 and their Galaxy Populations \|Fassbender, Rene, \| PhDT \| 0-116 \| 2008 \| 2008PhDT.......116F \| http://ui.adsabs.harvard.edu/#abs/2008PhDT.......116F The Hunt for Red Quasars: Luminous Obscured Black Hole Growth Unveiled in the Stripe 82 X-Ray Survey \|LaMassa, Stephanie M., Glikman, Eilat, et al. \| ApJ \| 847-100 \| 2017 \| 2017ApJ...847..100L \| http://ui.adsabs.harvard.edu/#abs/2017ApJ...847..100L Anisotropy of the galaxy cluster X-ray luminosity-temperature relation \|Migkas, Konstantinos, Reiprich, Thomas H., \| A&A \| 611-50 \| 2018 \| 2018A&A...611A..50M \| http://ui.adsabs.harvard.edu/#abs/2018A&A...611A..50M Luminous WISE-selected Obscured, Unobscured, and Red Quasars in Stripe 82 \|Glikman, E., Lacy, M., et al. \| ApJ \| 861-37 \| 2018 \| 2018ApJ...861...37G \| http://ui.adsabs.harvard.edu/#abs/2018ApJ...861...37G The XMM Cluster Survey: Present status and latest results \|Viana, P. T. P., Mehrtens, N., et al. \| AN \| 334-462 \| 2013 \| 2013AN....334..462V \| http://ui.adsabs.harvard.edu/#abs/2013AN....334..462V Chandra Multi-Wavelength Project: Normal Galaxies at Intermediate Redshift \|Kim, D.-W., Green, P. J., et al. \| ChJAS \| 8-138 \| 2008 \| 2008ChJAS...8..138K \| http://ui.adsabs.harvard.edu/#abs/2008ChJAS...8..138K The Massive and Distant Clusters of WISE Survey. I. Survey Overview and a Catalog of >2000 Galaxy Clusters at z virgul= 1 \|Gonzalez, Anthony H., Gettings, Daniel P., et al. \| ApJS \| 240-33 \| 2019 \| 2019ApJS..240...33G \| http://ui.adsabs.harvard.edu/#abs/2019ApJS..240...33G Testing emergent gravity on galaxy cluster scales \|Tamosiunas, Andrius, Bacon, David, et al. \| JCAP \| 5-53 \| 2019 \| 2019JCAP...05..053T \| http://ui.adsabs.harvard.edu/#abs/2019JCAP...05..053T Chandra Follow-up of the SDSS DR8 Redmapper Catalog Using the MATCha Pipeline \|Hollowood, Devon L., Jeltema, Tesla, et al. \| ApJS \| 244-22 \| 2019 \| 2019ApJS..244...22H \| http://ui.adsabs.harvard.edu/#abs/2019ApJS..244...22H Stellar mass as a galaxy cluster mass proxy: application to the Dark Energy Survey redMaPPer clusters \|Palmese, A., Annis, J., et al. \| MNRAS \| 493-4591 \| 2020 \| 2020MNRAS.493.4591P \| http://ui.adsabs.harvard.edu/#abs/2020MNRAS.493.4591P X-ray properties of the X-CLASS-redMaPPer galaxy cluster sample: the luminosity-temperature relation \|Molham, Mona, Clerc, Nicolas, et al. \| MNRAS \| 494-161 \| 2020 \| 2020MNRAS.494..161M \| http://ui.adsabs.harvard.edu/#abs/2020MNRAS.494..161M Accretion History of AGNs. II. Constraints on AGN Spectral Parameters Using the Cosmic X-Ray Background \|Ananna, Tonima Tasnim, Treister, Ezequiel, et al. \| ApJ \| 889-17 \| 2020 \| 2020ApJ...889...17A \| http://ui.adsabs.harvard.edu/#abs/2020ApJ...889...17A A Comparison of X-Ray Photon Indices among the Narrow- and Broad-line Seyfert 1 Galaxies \|Ojha, Vineet, Chand, Hum, et al. \| ApJ \| 896-95 \| 2020 \| 2020ApJ...896...95O \| http://ui.adsabs.harvard.edu/#abs/2020ApJ...896...95O Multiwavelength classification of X-ray selected galaxy cluster candidates using convolutional neural networks \|Kosiba, Matej, Lieu, Maggie, et al. \| MNRAS \| 496-4141 \| 2020 \| 2020MNRAS.496.4141K \| http://ui.adsabs.harvard.edu/#abs/2020MNRAS.496.4141K SPIDERS: overview of the X-ray galaxy cluster follow-up and the final spectroscopic data release \|Clerc, N., Kirkpatrick, C. C., et al. \| MNRAS \| 497-3976 \| 2020 \| 2020MNRAS.497.3976C \| http://ui.adsabs.harvard.edu/#abs/2020MNRAS.497.3976C A Luminous X-Ray Transient in SDSS J143359.16+400636.0: A Likely Tidal Disruption Event \|Brightman, Murray, Ward, Charlotte, et al. \| ApJ \| 909-102 \| 2021 \| 2021ApJ...909..102B \| http://ui.adsabs.harvard.edu/#abs/2021ApJ...909..102B Classification of 4XMM-DR9 sources by machine learning \|Zhang, Yanxia, Zhao, Yongheng, \| MNRAS \| 503-5263 \| 2021 \| 2021MNRAS.503.5263Z \| http://ui.adsabs.harvard.edu/#abs/2021MNRAS.503.5263Z X-ray emission from a rapidly accreting narrow-line Seyfert 1 galaxy at z = 6.56 \|Wolf, J., Nandra, K., et al. \| A&A \| 669-127 \| 2023 \| 2023A&A...669A.127W \| http://ui.adsabs.harvard.edu/#abs/2023A&A...669A.127W On the Cosmic Evolution of AGN Obscuration and the X-Ray Luminosity Function: XMM-Newton and Chandra Spectral Analysis of the 31.3 degSUP_OPEN2SUP_CLOSE Stripe 82X \|Peca, Alessandro, Cappelluti, Nico, et al. \| ApJ \| 943-162 \| 2023 \| 2023ApJ...943..162P \| http://ui.adsabs.harvard.edu/#abs/2023ApJ...943..162P The Accretion History of AGN: The Spectral Energy Distributions of X-Ray-luminous Active Galactic Nuclei \|Auge, Connor, Sanders, David, et al. \| ApJ \| 957-19 \| 2023 \| 2023ApJ...957...19A \| http://ui.adsabs.harvard.edu/#abs/2023ApJ...957...19A A Statistical Study of Soft X-Ray Flares on Solar-type Stars \|Zhao, Z. H., Hua, Z. Q., et al. \| ApJ \| 961-130 \| 2024 \| 2024ApJ...961..130Z \| http://ui.adsabs.harvard.edu/#abs/2024ApJ...961..130Z The XMM-Newton Line Emission Analysis Program (X-LEAP). I. Emission-line Survey of O VII, O VIII, and Fe L-shell Transitions \|Pan, Zeyang, Qu, Zhijie, et al. \| ApJS \| 271-62 \| 2024 \| 2024ApJS..271...62P \| http://ui.adsabs.harvard.edu/#abs/2024ApJS..271...62P From Active Stars to Black Holes: A Discovery Tool for Galactic X-Ray Sources \|Rodriguez, Antonio C., \| PASP \| 136-054201 \| 2024 \| 2024PASP..136e4201R \| http://ui.adsabs.harvard.edu/#abs/2024PASP..136e4201R Robust constraints on feebly interacting particles using XMM-Newton \|Luque, Pedro De la Torre, Balaji, Shyam, \| PhRvD \| 109-L101305 \| 2024 \| 2024PhRvD.109j1305L \| http://ui.adsabs.harvard.edu/#abs/2024PhRvD.109j1305L Multimessenger search for electrophilic feebly interacting particles from supernovae \|Luque, Pedro De la Torre, Balaji, Shyam, \| PhRvD \| 109-103028 \| 2024 \| 2024PhRvD.109j3028L \| http://ui.adsabs.harvard.edu/#abs/2024PhRvD.109j3028L Importance of Cosmic-Ray Propagation on Sub-GeV Dark Matter Constraints \|De la Torre Luque, Pedro, Balaji, Shyam, \| ApJ \| 968-46 \| 2024 \| 2024ApJ...968...46D \| http://ui.adsabs.harvard.edu/#abs/2024ApJ...968...46D
Instrument	EMOS1, EMOS2, EPN, OM, RGS1, RGS2
Temporal Coverage	2002-02-22T08:11:57Z/2002-02-22T14:33:09Z
Version	17.56_20190403_1200
Mission Description	The European Space Agencys (ESA) X-ray Multi-Mirror Mission (XMM-Newton) was launched by an Ariane 504 on December 10th 1999. XMM-Newton is ESAs second cornerstone of the Horizon 2000 Science Programme. It carries 3 high throughput X-ray telescopes with an unprecedented effective area, and an optical monitor, the first flown on a X-ray observatory. The large collecting area and ability to make long uninterrupted exposures provide highly sensitive observations. Since Earths atmosphere blocks out all X-rays, only a telescope in space can detect and study celestial X-ray sources. The XMM-Newton mission is helping scientists to solve a number of cosmic mysteries, ranging from the enigmatic black holes to the origins of the Universe itself. Observing time on XMM-Newton is being made available to the scientific community, applying for observational periods on a competitive basis.
Creator Contact	https://www.cosmos.esa.int/web/xmm-newton/xmm-newton-helpdesk
Date Published	2003-03-30T00:00:00Z
Keywords	"SDSS", "xray luminosity function", "additional sdss quasars", "redshift quasars", "basic xray properties", "objects bright", "distant quasars", "xray spectroscopy", "date z", "systematic xray", "effective manner", "sdss quasars"
Publisher And Registrant	European Space Agency
Credit Guidelines	European Space Agency, Prof William Brandt, 2003, 'An X-ray Study of the Most Distant Quasars from the Sloan Digital Sky Survey', 17.56_20190403_1200, European Space Agency, https://doi.org/10.5270/esa-zyq469l