Chandra X-rays from the redshift 7.54 quasar ULAS J1342+0928

Abstract

We present a 45 ks Chandra observation of the quasar ULAS J1342+0928 at z=7.54. We detect 14.0^{+4.8}_{-3.7} counts from the quasar in the observed-frame energy range 0.5-7.0 keV (6-sigma detection), representing the most distant non-transient astronomical source identified in X-rays to date. The present data are sufficient only to infer rough constraints on the spectral parameters. We find an X-ray hardness ratio of HR = -0.51^{+0.26}_{-0.28} between the 0.5-2.0 keV and 2.0-7.0 keV ranges and derive a power-law photon index of Gamma = 1.95^{+0.55}_{-0.53}. Assuming a typical value for high-redshift quasars of Gamma = 1.9, ULAS J1342+0928 has a 2-10 keV rest-frame X-ray luminosity of L_{2-10} = 11.6^{+4.3}_{-3.5} x 10^{44} erg/s. Its X-ray-to-optical power-law slope is alpha_{OX}=-1.67^{+0.16}_{-0.10}, consistent with the general trend indicating that the X-ray emission in the most bolometrically powerful quasars is weaker relative to their optical emission.

arXiv commentAccepted for publication in the Astrophysical Journal Letters

References in corpus (40)

• The Astropy Project: Building an inclusive, open-science project and status of the v2.0 core package
• The Leiden/Argentine/Bonn (LAB) Survey of Galactic HI: Final data release of the combined LDS and IAR surveys with improved stray-radiation corrections
• An 800-million-solar-mass black hole in a significantly neutral Universe at redshift 7.5
• A glimpse of the end of the dark ages: the gamma-ray burst of 23 April 2009 at redshift 8.3
• A Wavelet-Based Algorithm for the Spatial Analysis of Poisson Data
• A light bending model for the X-ray temporal and spectral properties of accreting black holes
• Unification of Luminous Type 1 Quasars through CIV Emission
• The X-ray Properties of the Most-Luminous Quasars from the Sloan Digital Sky Survey
• The Pan-STARRS1 distant z>5.6 quasar survey: more than 100 quasars within the first Gyr of the universe
• Bayesian Estimation of Hardness Ratios: Modeling and Computations
• The Formation and Evolution of Massive Black Holes
• Physical properties of 15 quasars at $z\gtrsim 6.5$
• A Hubble Diagram for Quasars
• The tight relation between X-ray and ultraviolet luminosity of quasars
• A statistical relation between the X-ray spectral index and Eddington ratio of active galactic nuclei in deep surveys
• The WISSH Quasars Project I. Powerful ionised outflows in hyper-luminous quasars
• X-ray Insights into the Nature of PHL 1811 Analogs and Weak Emission-Line Quasars: Unification with a Geometrically Thick Accretion Disk?
• Quasars as standard candles I: The physical relation between disc and coronal emission
• The X-Ray to Mid-Infrared Relation of AGN at High Luminosity
• Spectral Energy Distributions of QSOs at z>5: common AGN-heated dust and occasionally strong star-formation
• Copious Amounts of Dust and Gas in a z=7.5 Quasar Host Galaxy
• Constraining the radio-loud fraction of quasars at z>5.5
• Chandra Observations of the Highest Redshift Quasars from the Sloan Digital Sky Survey
• A survey of luminous high-redshift quasars with SDSS and WISE. I. target selection and optical spectroscopy
• The X-ray properties of z$\sim$6 luminous quasars
• The WISSH Quasars Project III. X-ray properties of hyper-luminous quasars
• The WISSH quasars Project: II. Giant star nurseries in hyper-luminous quasars
• Weak Hard X-ray Emission from Two Broad Absorption Line Quasars Observed with NuSTAR: Compton-thick Absorption or Intrinsic X-ray Weakness?
• NuSTAR Observations of Heavily Obscured Quasars at z ~ 0.5
• Exploratory Chandra Observations of the Three Highest Redshift Quasars Known
• Heavy X-ray obscuration in the most-luminous galaxies discovered by WISE
• The X-ray and Mid-Infrared luminosities in Luminous Type 1 Quasars
• X-rays from the redshift 7.1 quasar ULAS J1120+0641
• Discovery of an Optically-Faint Quasar at z=5.70 and Implications for the Faint End of the Quasar Luminosity Function
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• X-ray observation of ULAS J1120+0641, the most distant quasar at z=7.08
• The Innermost Extremes of Black Hole Accretion
• X-ray spectroscopy of the z=6.4 quasar J1148+5251
• Exploratory Chandra observation of the ultraluminous quasar SDSS J010013.02+280225.8 at redshift 6.30
• XMM-Newton observation of the ultraluminous quasar SDSS J010013.02+280225.8 at redshift 6.326

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