Using Leaked Power to Measure Intrinsic AGN Power Spectra of Red-Noise Time Series

Abstract

Fluxes emitted at different wavebands from active galactic nuclei (AGNs) fluctuate at both long and short timescales. The variation can typically be characterized by a broadband power spectrum, which exhibits a red-noise process at high frequencies. The standard method of estimating power spectral density (PSD) of AGN variability is easily affected by systematic biases such as red-noise leakage and aliasing, in particular, when the observation spans a relatively short period and is gapped. Focusing on the high-frequency PSD that is strongly distorted due to red-noise leakage and usually not significantly affected by aliasing, we develop a novel and observable normalized leakage spectrum (NLS), which describes sensitively the effects of leaked red-noise power on the PSD at different temporal frequencies. Using Monte Carlo simulations, we demonstrate how an AGN underlying PSD sensitively determines the NLS when there is severe red-noise leakage and thereby how the NLS can be used to effectively constrain the underlying PSD.

arXiv commentAccepted for publication in ApJ (14 pages, 13 figures, 1 table)

References in corpus (30)

• On characterising the variability properties of X-ray light curves from active galaxies
• Are the Variations in Quasar Optical Flux Driven by Thermal Fluctuations?
• Active Galactic Nuclei as scaled-up Galactic black holes
• X-ray reverberation around accreting black holes
• Non-linear X-ray variability in X-ray binaries and active galaxies
• Measuring the broadband power spectra of active galactic nuclei with RXTE
• Combined Long and Short Timescale X-ray Variability of NGC4051 with RXTE and XMM-Newton
• An Alternative Approach To Measuring Reverberation Lags in Active Galactic Nuclei
• Is Quasar Optical Variability a Damped Random Walk?
• Generating artificial light curves: Revisited and updated
• Flexible and Scalable Methods for Quantifying Stochastic Variability in the Era of Massive Time-Domain Astronomical Data Sets
• X-ray Fluctuation Power Spectral Densities of Seyfert 1 Galaxies
• CAIXA: a catalogue of AGN in the XMM-Newton archive III. Excess Variance Analysis
• Kepler Observations of Rapid Optical Variability in Active Galactic Nuclei
• X-ray variability of 104 active galactic nuclei. XMM-Newton power-spectrum density profiles
• Fermi Gamma-ray Space Telescope Observations of the Gamma-ray Outburst from 3C 454.3 in November 2010
• A Bayesian test for periodic signals in red noise
• Discovery of multiple Lorentzian components in the X-ray timing properties of the Narrow Line Seyfert 1 Ark 564
• A method for the estimation of the significance of cross-correlations in unevenly sampled red-noise time series
• A Stochastic Model for the Luminosity Fluctuations of Accreting Black Holes
• Are the Variability Properties of the Kepler AGN Light Curves Consistent with a Damped Random Walk?
• Quasar Selection Based on Photometric Variability
• Calibrating the correlation between black hole mass and X-ray variability amplitude: X-ray only black hole mass estimates for active galactic nuclei and ultra-luminous X-ray sources
• X-ray Flaring Activity of Mrk 421
• Discovery of a ~5 day characteristic timescale in the Kepler power spectrum of Zw 229-15
• Kepler observations of rapid optical variability in the BL Lac object W2R1926+42
• A new cosmological distance measure using AGN X-ray variability
• X-ray Flares from Markarian 501
• Short Timescale AGN X-ray Variability with EXOSAT: Black hole mass and Normalised Variability Amplitude
• Accretion, ejection and reprocessing in supermassive black holes

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• Characterising X-ray variability in light curves with complex sampling patterns: application to the eROSITA south ecliptic pole survey
• Decade-long periodicity study of 2FHL blazars with historical optical data
• The Feasibility and Flexibility of Selecting Quasars by Variability Using Ensemble Machine Learning Algorithms
• Estimating longterm power spectral densities in AGN from simulations