A new physical interpretation of optical and infrared variability in quasars

Abstract

Changing-look quasars are a recently identified class of active galaxies in which the strong UV continuum and/or broad optical hydrogen emission lines associated with unobscured quasars either appear or disappear on timescales of months to years. The physical processes responsible for this behaviour are still debated, but changes in the black hole accretion rate or accretion disk structure appear more likely than changes in obscuration. Here we report on four epochs of spectroscopy of SDSS J110057.70-005304.5, a quasar at a redshift of $z=0.378$ whose UV continuum and broad hydrogen emission lines have faded, and then returned over the past $\approx$20 years. The change in this quasar was initially identified in the infrared, and an archival spectrum from 2010 shows an intermediate phase of the transition during which the flux below rest-frame $\approx$3400Å has decreased by close to an order of magnitude. This combination is unique compared to previously published examples of changing-look quasars, and is best explained by dramatic changes in the innermost regions of the accretion disk. The optical continuum has been rising since mid-2016, leading to a prediction of a rise in hydrogen emission line flux in the next year. Increases in the infrared flux are beginning to follow, delayed by a $\sim$3 year observed timescale. If our model is confirmed, the physics of changing-look quasars are governed by processes at the innermost stable circular orbit (ISCO) around the black hole, and the structure of the innermost disk. The easily identifiable and monitored changing-look quasars would then provide a new probe and laboratory of the nuclear central engine.

arXiv comment13 pages, 4 figures, 3 tables. Published in MNRAS. All code and data links on GitHub, https://github.com/d80b2t/WISE_LC

References in corpus (75)

• The Wide-field Infrared Survey Explorer (WISE): Mission Description and Initial On-orbit Performance
• The Galaxy Evolution Explorer: A Space Ultraviolet Survey Mission
• The Baryon Oscillation Spectroscopic Survey of SDSS-III
• Hot Accretion Flows Around Black Holes
• A Catalog of Quasar Properties from SDSS DR7
• First Results from the Catalina Real-time Transient Survey
• Spectral Energy Distributions and Multiwavelength Selection of Type 1 Quasars
• The Pan-STARRS1 Photometric System
• Spectroscopic Target Selection in the Sloan Digital Sky Survey: The Quasar Sample
• LSST Science Book, Version 2.0
• Preliminary Results from NEOWISE: An Enhancement to the Wide-field Infrared Survey Explorer for Solar System Science
• Initial Performance of the NEOWISE Reactivation Mission
• Modeling the Time Variability of SDSS Stripe 82 Quasars as a Damped Random Walk
• Foundations of Black Hole Accretion Disk Theory
• The SuperCOSMOS Sky Survey. Paper I: Introduction and Description
• First Data Release of the Hyper Suprime-Cam Subaru Strategic Program
• Accretion disc viscosity: how big is alpha?
• Second ROSAT all-sky survey (2RXS) source catalogue
• The Ensemble Photometric Variability of ~25000 Quasars in the Sloan Digital Sky Survey
• The Sloan Digital Sky Survey Quasar Catalog IV. Fifth Data Release
• Measuring Black Hole Spin using X-ray Reflection Spectroscopy
• The Sloan Digital Sky Survey Quasar Catalog: twelfth data release
• A General Class of Lagrangian Smoothed Particle Hydrodynamics Methods and Implications for Fluid Mixing Problems
• The Discovery of the First "Changing Look" Quasar: New Insights into the Physics & Phenomenology of AGN
• The Quasar Accretion Disk Size - Black Hole Mass Relation
• The Quasar Accretion Disk Size -- Black Hole Mass Relation
• unWISE: unblurred coadds of the WISE imaging
• The Pan-STARRS 1 Photometric Reference Ladder, Release 12.0
• A Systematic Search for Changing-Look Quasars in SDSS
• General Relativistic Hydrodynamic Simulation of Accretion Flow from a Stellar Tidal Disruption
• The SDSS-III Baryon Oscillation Spectroscopic Survey: Quasar Target Selection for Data Release Nine
• Magnetic Stress at the Marginally Stable Orbit: Altered Disk Structure, Radiation, and Black Hole Spin Evolution
• New white dwarf and subdwarf stars in the Sloan Digital Sky Survey Data Release 12
• New white dwarf stars in the Sloan Digital Sky Survey Data Release 10
• The WISE AGN Catalog
• Reverberation Measurements of the Inner Radius of the Dust Torus in 17 Seyfert Galaxies
• The SuperCOSMOS Sky Survey. Paper II: Image detection, parameterisation, classification and photometry
• Spectral energy distributions of selfgravitating QSO discs
• Discovery of 21 New Changing-look AGNs in Northern Sky
• Efficiency of Magnetized Thin Accretion Disks in the Kerr Metric
• X-Ray and Optical Flux Ratio Anomalies in Quadruply Lensed Quasars: I. Zooming in on Quasar Emission Regions
• Intermediate mass black holes in AGN disks II. Model predictions & observational constraints
• The Sloan Digital Sky Survey Quasar Catalog I. Early Data Release
• Dust inflated accretion disc as the origin of the Broad Line Region in Active Galactic Nuclei
• Towards an Understanding of Changing-Look Quasars: An Archival Spectroscopic Search in SDSS
• Quasars as standard candles I: The physical relation between disc and coronal emission
• The Microlensing Properties of a Sample of 87 Lensed Quasars
• The SDSS/XMM-Newton Quasar Survey: Correlation between X-ray spectral slope and Eddington ratio
• Precise Throughput Determination of the PanSTARRS Telescope and the Gigapixel Imager using a Calibrated Silicon Photodiode and a Tunable Laser: Initial Results
• Multi-Temperature Blackbody Spectra of Thin Accretion Disks With and Without a Zero-Torque Inner Boundary Condition
• Further Evidence that Quasar X-Ray Emitting Regions Are Compact: X-Ray and Optical Microlensing in the Lensed Quasar Q J0158-4325
• Quasar Viscosity Crisis
• Radiatively Inefficient Accretion Flow in the Nucleus of NGC 1097
• Deep Full-sky Coadds from Three Years of WISE and NEOWISE Observations
• Geometrically Thin Disk Accreting Into a Black Hole
• Characteristic QSO Accretion Disk Temperatures from Spectroscopic Continuum Variability
• The Prevalence of Gas Outflows in Type 2 AGNs. II. 3D Biconical Outflow Models
• The UV peak in Active Galactic Nuclei : a false continuum from blurred reflection ?
• Rest-frame Optical Spectra and Black Hole Masses of 3<z<6 Quasars
• QSFit: Automatic analysis of optical AGN spectra
• Black hole accretion discs
• On the Radial Structure of Radiatively Inefficient Accretion Flows with Convection
• Active galactic nuclei at z ~ 1.5: III. Accretion discs and black hole spin
• Advection-Dominated Accretion around Black Holes
• General Relativistic Hydrodynamic Simulations and Linear Analysis of the Standing Accretion Shock Instability around a Black Hole
• Improved Spectrophotometric Calibration of the SDSS-III BOSS Quasar Sample
• On the M_V(peak) Versus Orbital Period Relation for Dwarf Nova Outbursts
• The thermal-viscous disk instability model in the AGN context
• The Zwicky Transient Facility
• The optical variability of SDSS quasars from multi-epoch spectroscopy. II. color variation
• Searching for Planet Nine with Coadded WISE and NEOWISE-Reactivation Images
• The Optical Variability of SDSS Quasars from Multi-epoch Spectroscopy. III. A Sudden UV Cutoff in Quasar SDSS J2317+0005
• Quasars with Anomalous Hβ Profiles I: Demographics
• Thermal AGN Signatures in Blazars
• The radiation properties of an accretion disk with a non-zero torque on its inner edge

Cited by in corpus (79)

• Candidate Electromagnetic Counterpart to the Binary Black Hole Merger Gravitational Wave Event S190521g
• The Automatic Learning for the Rapid Classification of Events (ALeRCE) Alert Broker
• 1ES 1927+654: An AGN Caught Changing Look on a Timescale of Months
• Changing-Look Quasar Candidates: First Results from Follow-up Spectroscopy of Highly Optically Variable Quasars
• A possible mechanism for multiple changing look phenomenon in Active Galactic Nuclei
• Extreme AGN variability: evidence of magnetically elevated accretion?
• The Analogous Structure of Accretion Flows in Supermassive and Stellar Mass Black Holes: New Insights from Faded Changing-Look Quasars
• Understanding extreme quasar optical variability with CRTS: II. Changing-state quasars
• The large and small scale properties of the intergalactic gas in the Slug Ly-alpha nebula revealed by MUSE HeII emission observations
• A New Class of Changing-Look LINERs
• Repeating tidal disruptions in GSN 069: Long-term evolution and constraints on quasi-periodic eruptions' models
• Improving Damped Random Walk parameters for SDSS Stripe 82 Quasars with Pan-STARRS1
• A light in the dark: searching for electromagnetic counterparts to black hole-black hole mergers in LIGO/Virgo O3 with the Zwicky Transient Facility
• A Family Tree of Optical Transients from Narrow-Line Seyfert 1 Galaxies
• Magnetically Dominated Disks in Tidal Disruption Events and Quasi-Periodic Eruptions
• unWISE Coadds: The Five-year Data Set
• The 450 days X-ray monitoring of the changing-look AGN 1ES 1927+654
• Modified models of radiation pressure instability in application to 10, 10${}^5$, and 10${}^7$ $M_{\odot }$ accreting black holes
• unTimely: a Full-sky, Time-Domain unWISE Catalog
• Exploring Changing-look Active Galactic Nuclei with the Sloan Digital Sky Survey V: First Year Results
• Discovery of A Mg II Changing-look AGN and its Implications for a Unification Sequence of Changing-look AGNs
• Searching for changing-state AGNs in massive datasets -- I: applying deep learning and anomaly detection techniques to find AGNs with anomalous variability behaviours
• The Sloan Digital Sky Survey Reverberation Mapping Project: Accretion and Broad Emission Line Physics from a Hypervariable Quasar
• AT 2019avd: A novel addition to the diverse population of nuclear transients
• Changing-look active galactic nuclei: close binaries of supermassive black holes in action
• Evolution of a Relativistic Outflow and X-ray Corona in the Extreme Changing-Look AGN 1ES 1927+654
• BASS XXXIX: Swift-BAT AGN with changing-look optical spectra
• The first high-redshift changing-look quasars
• Confirming new changing--look AGNs discovered through optical variability using a random-forest based light curve classifier
• Deep modeling of quasar variability
• Evolution of Retrograde Orbiters in an AGN Disk
• Velocity-resolved Reverberation Mapping of Changing-look AGN NGC 2617
• Two New "Turn-off" Changing-look Active Galactic nuclei and Implication on "Partially Obscured" AGNs
• MUSE observations of a changing-look AGN I: The re-appearance of the broad emission lines
• The Near and Mid-infrared photometric properties of known redshift $z\ge 5$ Quasars
• Starfall: A heavy rain of stars in 'turning on' AGN
• The effects of large-scale magnetic fields on the model for repeating changing-look AGNs
• A Luminous Transient Event in a Sample of WISE-Selected Variable AGN
• Rapid Luminosity Decline and Subsequent Reformation of the Innermost Dust Distribution in the Changing-look AGN Mrk 590
• Spectral Variability of a Sample of Extreme Variability Quasars and Implications for the MgII Broad-line Region
• An Unusual Mid-Infrared Flare in a Type 2 AGN: An Obscured Turning-on AGN or Tidal Disruption Event?
• A forward modelling approach to AGN variability -- Method description and early applications
• Optical Emission Model for Binary Black Hole Merger Remnants Travelling through Discs of Active Galactic Nuclei
• Lifting the curtain: The Seyfert galaxy Mrk 335 emerges from deep low-state in a sequence of rapid flare events
• Discovery of Dying Active Galactic Nucleus in Arp 187: Experience of Drastic Luminosity Decline within $10^4$ years
• Discovery of the luminous X-ray ignition eRASSt J234402.9$-$352640; I. Tidal disruption event or a rapid increase in accretion in an active galactic nucleus?
• NuSTAR Observations of AGN with Low Observed X-ray to [OIII] Luminosity Ratios: Heavily Obscured AGN or Turned-Off AGN?
• Investigating Changing-Look Active Galactic Nuclei with Long-term Optical and X-Ray Observations
• Optical and X-ray discovery of the changing-look AGN IRAS23226-3843 showing extremely broad and double-peaked Balmer profiles
• Improving the selection of changing-look AGNs through multi-wavelength photometric variability
• Extreme Variability Quasars in Their Various States. I: The sample selection and composite SDSS spectra
• Tracking the year-to-year variation in the spectral energy distribution of the Narrow-line Seyfert 1 Galaxy Mrk335
• Gemini Imaging of the Host Galaxies of Changing-Look Quasars
• The transient event in NGC 1566 from 2017 to 2019 -- I. An eccentric accretion disk and a turbulent, disk-dominated broad-line region unveiled by double-peaked Ca II and O I lines
• Flares in the changing look AGN Mrk 590. I: The UV response to X-ray outbursts suggests a more complex reprocessing geometry than a standard disk
• Local Active Galactic Nuclei with Large Broad-Hα Variability Reside in Red Galaxies
• Host Galaxy Properties of Changing-look AGN Revealed in the MaNGA Survey
• Characterization of Optical Light Curves of Extreme Variability Quasars Over a ~16-yr Baseline
• A systematic search for changing-look quasars in SDSS-II using difference spectra
• Behaviour of the MgII 2798AA Line Over the Full Range of AGN Variability
• Extreme Accretion Events: TDEs and Changing-Look AGN
• A Systematic Survey for z < 0.04 Changing-Look AGNs
• The 'Big Dipper': The nature of the extreme variability of the AGN SDSS J2232-0806
• eROSITA Final Equatorial-Depth Survey (eFEDS): eFEDS X-ray view of WERGS Radio Galaxies selected by the Subaru/HSC and VLA/FIRST survey
• Suspended and restored activities of A Nearby Super Massive Black Hole
• Extreme Variability Quasars in Their Various States. II: Spectral Variation Revealed with Multi-epoch Spectra
• Long-term variability of the composite galaxy SDSS J103911-000057: A candidate of true Type-2 AGN
• Unveiling the quasar main sequence: illuminating the complexity of active galactic nuclei and their evolution
• Contribution of Flares from Tidal Disruption of Stars to high-redshift AGN
• On the Origin of the Dramatic Spectral Variability of WPVS 007
• AstroSat view of spectral transition in the changing-look active galaxy NGC1566 during the declining phase of the 2018 outburst
• The Awakening Beast in the Seyfert 1 Galaxy KUG 1141+371 I
• Multi-wavelength properties of changing-state active galactic nuclei: I. the evolution of soft excess and X-ray continuum
• Processing GOTO data with the Rubin Observatory LSST Science Pipelines I : Production of coadded frames
• SDSS-IV MaNGA: Identification and Multiwavelength Properties of Type-1 AGN in the DR15 sample
• Swift, NuStar and XMM-Newton observations of the NLS1 galaxy RX J2317.8-4422 in an extreme X-ray low flux state
• Identifying Changing-Look AGN Transitions in Light Curve Data with the Zwicky Transient Facility
• A magnetically-supported disk-corona model for Changing-Look AGN transitions
• Thermomagnetic Ettingshausen-Nernst effect in tachocline, magnetic reconnection phenomenon in lower layers, axion mechanism of solar luminosity variations, coronal heating problem solution and mechanism of ADM variations around BH