High frequency breaks in optical active galactic nuclei power spectral density
arXiv:2306.17334 · doi:10.1051/0004-6361/202452469
Abstract
Context. Variability is a ubiquitous feature of active galactic nuclei (AGNs), and the characterisation of the variability is crucial to constrain its physical mechanism and proper applications in AGN studies. The advent of all-sky and high-cadence optical surveys allows more accurate measurements of AGNs variability down to short timescales and direct comparisons with X-ray variability from the same sample of sources. Aims. We aim to analyse the optical power spectral density (PSDs) of AGNs with measured X-ray PSDs. Methods. We use light curves from the All-Sky Automated Survey for SuperNovae (ASAS-SN) and the Transiting Exoplanet Survey Satellite (TESS) and use the Lomb-Scargle periodogram to obtain PSDs. The joint optical PSD is measured over up to six orders of magnitude in frequency space from timescales of minutes to a decade. We fit either a damped random walk (DRW) or a broken power law (BPL) model to constrain the PSD model and break frequency. Results. We find a set of break frequencies ( day) from DRW and BPL fits that generally confirm previously reported correlations between break frequencies and the black hole mass. In addition, we find a second set of break frequencies at higher frequencies ( day). We observe a potential weak correlation between the high-frequency breaks with the X-ray break frequencies and black hole mass. We further explore the dependence of the correlations on other AGN parameters, finding that adding either X-ray, optical, or bolometric luminosity as the third correlation parameter can substantially improve the correlation significances. The newly identified high-frequency optical breaks can constrain different aspects of the physics of active galactic nuclei.
21 pages, 24 figures, accepted by A&A
References in corpus (45)
- The Astropy Project: Sustaining and Growing a Community-oriented Open-source Project and the Latest Major Release (v5.0) of the Core Package
- Reverberation Measurements for 17 Quasars and the Size-Mass-Luminosity Relations in Active Galactic Nuclei
- The Man Behind the Curtain: X-rays Drive the UV through NIR Variability in the 2013 AGN Outburst in NGC 2617
- Local Supermassive Black Holes, Relics of Active Galactic Nuclei and the X-ray Background
- On characterising the variability properties of X-ray light curves from active galaxies
- The All-Sky Automated Survey for Supernovae (ASAS-SN) Light Curve Server v1.0
- 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
- Central Masses and Broad-Line Region Sizes of Active Galactic Nuclei: I. Comparing the Photoionization and Reverberation Techniques
- The Ensemble Photometric Variability of ~25000 Quasars in the Sloan Digital Sky Survey
- Measuring the broadband power spectra of active galactic nuclei with RXTE
- The ASAS-SN Catalog of Variable Stars I: The Serendipitous Survey
- Combined Long and Short Timescale X-ray Variability of NGC4051 with RXTE and XMM-Newton
- Quantifying Quasar Variability As Part of a General Approach To Classifying Continuously Varying Sources
- Is Quasar Optical Variability a Damped Random Walk?
- Multiwavelength Monitoring of the Dwarf Seyfert 1 Galaxy NGC 4395. I. A Reverberation-Based Measurement of the Black Hole Mass
- Space Telescope and Optical Reverberation Mapping Project. II. Swift and HST Reverberation Mapping of the Accretion Disk of NGC 5548
- Kepler Observations of Rapid Optical Variability in Active Galactic Nuclei
- The Sizes of the X-ray and Optical Emission Regions of RXJ1131-1231
- X-ray variability of 104 active galactic nuclei. XMM-Newton power-spectrum density profiles
- Quasar Accretion Disks Are Strongly Inhomogeneous
- The ASAS-SN Catalog of Variable Stars III: Variables in the Southern TESS Continuous Viewing Zone
- A characteristic optical variability timescale in astrophysical accretion disks
- Accretion disk reverberation with Hubble Space Telescope observations of NGC 4593: evidence for diffuse continuum lags
- Optimal Time-Series Selection of Quasars
- Revisiting Stochastic Variability of AGNs with Structure Functions
- Are the Variability Properties of the Kepler AGN Light Curves Consistent with a Damped Random Walk?
- Long-Term X-ray Spectral Variability in Seyfert 1 Galaxies
- X-ray/UV/optical variability of NGC 4593 with Swift: Reprocessing of X-rays by an extended reprocessor
- X-Ray and Optical Microlensing in the Lensed Quasar PG 1115+080
- The Kepler Light Curves of AGN: A Detailed Analysis
- Pan-STARRS1 variability of XMM-COSMOS AGN. II. Physical correlations and power spectrum analysis
- Quasar Selection Based on Photometric Variability
- Quasar Spectral Slope Variability in the Optical Band
- On the time variability of geometrically-thin black hole accretion disks I : the search for modes in simulated disks
- Characterizing the Optical Variability of Bright Blazars: Variability-Based Selection of Fermi AGN
- Accretion Disk Sizes from Continuum Reverberation Mapping of AGN Selected from the ZTF Survey
- Early Time Light Curves of Type Ia Supernovae Observed with TESS
- Correlated X-ray/Ultraviolet/Optical Variability in NGC 6814
- High-Cadence, Early-Time Observations of Core-Collapse Supernovae From the TESS Prime Mission
- Short time-scale optical variability properties of the largest AGN sample observed with Kepler/K2
- Optical Variability of the Dwarf AGN NGC 4395 from the Transiting Exoplanet Survey Satellite
- Update on the X-ray variability plane for active galactic nuclei: The role of the obscuration
- Ensemble power spectral density of SDSS quasars in UV/optical bands