The Kepler Light Curves of AGN: A Detailed Analysis

Abstract

We present a comprehensive analysis of 21 light curves of Type 1 AGN from the Kepler spacecraft. First, we describe the necessity and development of a customized pipeline for treating Kepler data of stochastically variable sources like AGN. We then present the light curves, power spectral density functions (PSDs), and flux histograms. The light curves display an astonishing variety of behaviors, many of which would not be detected in ground-based studies, including switching between distinct flux levels. Six objects exhibit PSD flattening at characteristic timescales which roughly correlate with black hole mass. These timescales are consistent with orbital timescales or freefall accretion timescales. We check for correlations of variability and high-frequency PSD slope with accretion rate, black hole mass, redshift and luminosity. We find that bolometric luminosity is anticorrelated with both variability and steepness of the PSD slope. We do not find evidence of the linear rms-flux relationships or lognormal flux distributions found in X-ray AGN light curves, indicating that reprocessing is not a significant contributor to optical variability at the 0.1-10% level.

arXiv comment39 pages including 2 appendices. Accepted for Publication in the Astrophysical Journal, with higher resolution figures

References in corpus (50)

• The Wide-field Infrared Survey Explorer (WISE): Mission Description and Initial On-orbit Performance
• The Leiden/Argentine/Bonn (LAB) Survey of Galactic HI: Final data release of the combined LDS and IAR surveys with improved stray-radiation corrections
• The K2 Mission: Characterization and Early results
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• The Palomar Transient Factory: System Overview, Performance and First Results
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• Are the Variations in Quasar Optical Flux Driven by Thermal Fluctuations?
• Modeling the Time Variability of SDSS Stripe 82 Quasars as a Damped Random Walk
• Active Galactic Nuclei as scaled-up Galactic black holes
• Second ROSAT all-sky survey (2RXS) source catalogue
• Measuring the broadband power spectra of active galactic nuclei with RXTE
• X-ray Spectral Variability and Rapid Variability of the Soft X-ray Spectrum Seyfert 1 Galaxies Ark 564 and Ton S180
• Quantifying Quasar Variability As Part of a General Approach To Classifying Continuously Varying Sources
• Is Quasar Optical Variability a Damped Random Walk?
• The flux-dependent amplitude of broadband noise variability in X-ray binaries and active galaxies
• The first XMM-Newton slew survey catalogue: XMMSL1
• Updating quasar bolometric luminosity corrections
• Long-term optical variability properties of the Palomar-Green quasars
• Kepler Observations of Rapid Optical Variability in Active Galactic Nuclei
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• A Cutoff in the X-ray Fluctuation Power Density Spectrum of the Seyfert 1 Galaxy NGC 3516
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• Revisiting Stochastic Variability of AGNs with Structure Functions
• On the variability of quasars: a link between Eddington ratio and optical variability?
• Long-Term X-ray Spectral Variability in Seyfert 1 Galaxies
• Quasar Optical Variability in the Palomar-QUEST Survey
• Optical variability of AGN in the PTF/iPTF survey
• Pan-STARRS1 variability of XMM-COSMOS AGN. II. Physical correlations and power spectrum analysis
• Accretion-induced variability links young stellar objects, white dwarfs, and black holes
• The correlations between optical variability and physical parameters of quasars in SDSS Stripe 82
• Broad-Line Reverberation in the Kepler-Field Seyfert Galaxy Zw 229-015
• QSO variability: probing the Starburst model
• Reliable Identifications of AGN from the WISE, 2MASS and Rosat all-sky surveys
• The dependence of quasar variability on black hole mass
• On the time variability of geometrically-thin black hole accretion disks I : the search for modes in simulated disks
• Discovery of a ~5 day characteristic timescale in the Kepler power spectrum of Zw 229-15
• X-Ray Fluctuations from Locally Unstable Advection-Dominated Disks
• Quasar Black Hole Mass Estimates in the Era of Time Domain Astronomy
• Optical Variability of Narrow and Broad line Seyfert 1 galaxies
• Quasar Variability in the Framework of Poissonian Models
• The high frequency power spectrum of Markarian 766
• Variability of accretion flow in the core of the Seyfert galaxy NGC 4151
• Periodic accretion-powered flares from colliding EMRIs as TDE Imposters
• On rapid migration and accretion within disks around supermassive black holes
• Investigating Active Galactic Nuclei Variability Using Combined Multi-Quarter Kepler Data
• Pan-STARRS1 variability of XMM-COSMOS AGN. I. Impact on photometric redshifts
• Kepler Photometry of Four Radio-Loud AGN in 2010-2012
• The Ultraviolet/optical variability of steep-spectrum radio quasars: the change in accretion rate ?
• KSwAGS: A Swift X-ray and UV Survey of the Kepler Field. I

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