Tracing the accretion history of supermassive Black Holes through X-ray variability: results from the Chandra Deep Field-South

Abstract

We study the X-ray variability properties of distant AGNs in the Chandra Deep Field-South region over 17 years, up to $z\sim 4$, and compare them with those predicted by models based on local samples. We use the results of Monte Carlo simulations to account for the biases introduced by the discontinuous sampling and the low-count regime. We confirm that variability is an ubiquitous property of AGNs, with no clear dependence on the density of the environment. The variability properties of high-z AGNs, over different temporal timescales, are most consistent with a Power Spectral Density (PSD) described by a broken (or bending) power-law, similar to nearby AGNs. We confirm the presence of an anti-correlation between luminosity and variability, resulting from the dependence of variability on BH mass and accretion rate. We explore different models, finding that our acceptable solutions predict that BH mass influences the value of the PSD break frequency, while the Eddington ratio ${\lambda }_{Edd}$ affects the PSD break frequency and, possibly, the PSD amplitude as well. We derive the evolution of the average ${\lambda }_{Edd}$ as a function of redshift, finding results in agreement with measurements based on different estimators. The large statistical uncertainties make our results consistent with a constant Eddington ratio, although one of our models suggest a possible increase of ${\lambda }_{Edd}$ with lookback time up to $z\sim 2-3$. We conclude that variability is a viable mean to trace the accretion history of supermassive BHs, whose usefulness will increase with future, wide-field/large effective area X-ray missions.

arXiv comment15 pages, 9 Figures, 2 Tables, in press on MNRAS

References in corpus (59)

• First Year Wilkinson Microwave Anisotropy Probe (WMAP) Observations: Determination of Cosmological Parameters
• Local Supermassive Black Holes, Relics of Active Galactic Nuclei and the X-ray Background
• A Catalog of Quasar Properties from SDSS DR7
• On characterising the variability properties of X-ray light curves from active galaxies
• Are the Variations in Quasar Optical Flux Driven by Thermal Fluctuations?
• An ultra-luminous quasar with a twelve-billion-solar-mass black hole at redshift 6.30
• Modeling the Time Variability of SDSS Stripe 82 Quasars as a Damped Random Walk
• Active Galactic Nuclei as scaled-up Galactic black holes
• The Chandra Deep Field South: the 1 Million Second
• The Chandra Deep Field-South Survey: 4 Ms Source Catalogs
• The Chandra Deep Field-South Survey: 7 Ms Source Catalogs
• Measuring the broadband power spectra of active galactic nuclei with RXTE
• On the Estimation of Confidence Intervals for Binomial Population Proportions in Astronomy: The Simplicity and Superiority of the Bayesian Approach
• Bolometric luminosities and Eddington ratios of X-ray selected Active Galactic Nuclei in the XMM-COSMOS survey
• Combined Long and Short Timescale X-ray Variability of NGC4051 with RXTE and XMM-Newton
• PRIMUS: The dependence of AGN accretion on host stellar mass and color
• X-ray Fluctuation Power Spectral Densities of Seyfert 1 Galaxies
• The Chandra Deep Field-South Survey: 2 Ms Source Catalogs
• Accreting SMBHs in the COSMOS field and the connection to their host galaxies
• CAIXA: a catalogue of AGN in the XMM-Newton archive III. Excess Variance Analysis
• X-ray variability of 104 active galactic nuclei. XMM-Newton power-spectrum density profiles
• A statistical relation between the X-ray spectral index and Eddington ratio of active galactic nuclei in deep surveys
• X-rays across the galaxy population - II. The distribution of AGN accretion rates as a function of stellar mass and redshift
• On X-ray Variability in Seyfert Galaxies
• Tracing the large scale structure in the Chandra Deep Field South
• Discovery of multiple Lorentzian components in the X-ray timing properties of the Narrow Line Seyfert 1 Ark 564
• X-ray absorption by Broad Line Region Clouds in Mrk 766
• The sub-mJy radio sky in the Extended Chandra Deep Field South: source population
• The scaling of the X-ray variability with black hole mass in AGN
• Quasar Broad Absorption Line Variability on Multi-Year Time Scales
• The XMM-Newton long look of NGC 1365: uncovering of the obscured X-ray source
• Pan-STARRS1 variability of XMM-COSMOS AGN. II. Physical correlations and power spectrum analysis
• Broad Absorption Line Variability in Repeat Quasar Observations from the Sloan Digital Sky Survey
• Prevalence of X-ray variability in the Chandra Deep Field South
• XMM-Newton observations of the Lockman Hole V: time variability of the brightest AGN
• A New, Faint Population of X-ray Transients
• The deepest X-ray view of high-redshift galaxies: constraints on low-rate black-hole accretion
• The Evolution of Quasar CIV and SiIV Broad Absorption Lines Over Multi-Year Time Scales
• AGN X-ray variability in the XMM-COSMOS survey
• X-ray variability in a deep, flux limited sample of QSOs
• A new cosmological distance measure using AGN X-ray variability
• Variability Selected Low-Luminosity Active Galactic Nuclei in the 4 Ms Chandra Deep Field-South
• Ensemble X-ray variability of Active Galactic Nuclei. II. Excess Variance and updated Structure Function
• Variable X-ray absorption in the mini-BAL QSO PG 1126-041
• The X-Ray Variability of a Large, Serendipitous Sample of Spectroscopic Quasars
• Ensemble X-ray variability of Active Galactic Nuclei from serendipitous source catalogues
• Measuring X-ray variability in faint/sparsely-sampled AGN
• PRIMUS: An observationally motivated model to connect the evolution of the AGN and galaxy populations out to z~1
• The long-term X-ray variability properties of AGN in the Lockman Hole region
• Eddington ratio Distribution of X-ray selected broad-line AGNs at 1.0<z<2.2
• The X-ray variability of high redshift QSOs
• The effects of X-ray absorption variability in NGC 4395
• The Radio - X-ray relation as a star formation indicator: Results from the VLA--E-CDFS Survey
• Exploratory X-ray Monitoring of Luminous Radio-Quiet Quasars at High Redshift: Initial Results
• The scaling of X-ray variability with luminosity in Ultra-luminous X-ray sources
• The longest timescale X-ray variability reveals an evidence for active galactic nuclei in the high accretion state
• Deep-Survey Constraints on X-ray Outbursts from Galactic Nuclei
• Combined Long and Short Timescale X-ray Variability of NGC4051 with RXTE and XMM-Newton
• Waves and instabilities in an anisotropic universe

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