Quasars as standard candles II: The non linear relation between UV and X-ray emission at high redshifts

Abstract

A tight non-linear relation between the X-ray and the optical-ultraviolet (UV) emission has been observed in Active Galactic Nuclei (AGN) over a wide range of redshift and several orders of magnitude in luminosity, suggesting the existence of an ubiquitous physical mechanism regulating the energy transfer between the accretion disc and the X-ray emitting corona. Recently, our group developed a method to use this relation in the observational cosmology, turning quasars into standardizable candles. This work has the main aim to investigate the potential evolution of this correction at high redshifts. We thus studied the $L_{\mathrm{X}}-L_{\mathrm{UV}}$ relation for a sample of quasars in the redshift range 4<$z$<7, adopting the selection criteria proposed in our previous work regarding their spectral properties. The resulting sample consists of 53 Type 1 (unobscured) quasars, observed either with Chandra or XMM-Newton, for which we performed a full spectral analysis, determining the rest-frame 2 keV flux density, as well as more general X-ray properties such as the estimate of photon index, and the soft (0.5-2 keV) and hard (2-10 keV) unabsorbed luminosities. We find that the relation shows no evidence for evolution with redshift. The intrinsic dispersion of the L${}_X$-L${}_{UV}$ for a sample free of systematics/contaminants is of the order of 0.22 dex, which is consistent with previous estimates from our group on quasars at lower redshift.

17 pages, 5 figures, 2 appendices

References in corpus (17)

• Five-Year Wilkinson Microwave Anisotropy Probe (WMAP) Observations: Cosmological Interpretation
• A Catalog of Quasar Properties from SDSS DR7
• A luminous quasar at a redshift of z = 7.085
• An ultra-luminous quasar with a twelve-billion-solar-mass black hole at redshift 6.30
• The X-ray-to-Optical Properties of Optically-Selected Active Galaxies Over Wide Luminosity and Redshift Ranges
• The Sloan Digital Sky Survey Quasar Catalog: twelfth data release
• The X-ray Properties of the Most-Luminous Quasars from the Sloan Digital Sky Survey
• Baryon acoustic oscillations from the complete SDSS-III Ly$\alpha$-quasar cross-correlation function at $z=2.4$
• The first ultraviolet quasar stacked spectrum at z=2.4 from WFC3
• CAIXA: a Catalogue of AGN In the XMM-Newton Archive I. Spectral analysis
• Occultation measurement of the size of the X-ray emitting region in the Active Galactic Nucleus of NGC 1365
• Gemini Near-infrared Spectroscopy of Luminous z~6 Quasars: Chemical Abundances, Black Hole Masses, and MgII Absorption
• Chandra Observations of the Highest Redshift Quasars from the Sloan Digital Sky Survey
• Variability and the X-ray/UV ratio of Active Galactic Nuclei
• Cross-Calibration of the XMM-Newton EPIC pn & MOS On-Axis Effective Areas Using 2XMM Sources
• On inferring extinction laws in z~6 quasars as signatures of supernova dust
• Exploratory X-ray Monitoring of Luminous Radio-Quiet Quasars at High Redshift: No Evidence for Evolution in X-ray Variability

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