WISE view of changing-look AGNs: evidence for a transitional stage of AGNs

Abstract

The discovery of changing-look active galactic nuclei (CLAGNs) with the significant change of optical broad emission lines (optical CLAGNs) and/or strong variation of line-of-sight column densities (X-ray CLAGNs) challenges the orientation-based AGN unification model. We explore mid-infrared (mid-IR) properties for a sample of 57 optical CLAGNs and 11 X-ray CLAGNs based on the {\it Wide-field Infrared Survey Explorer} ({\it WISE}) archive data. We find that Eddington-scaled mid-IR luminosities of both optical and X-ray CLAGNs stay just between low-luminosity AGNs (LLAGNs) and luminous QSOs. The average Eddington-scaled mid-IR luminosities for optical and X-ray CLAGNs are $\sim 0.4$\% and $\sim 0.5$\%, respectively, which roughly correspond the bolometric luminosity of transition between a radiatively inefficient accretion flow (RIAF) and Shakura-Sunyaev disk (SSD). We estimate the time lags of the variation in the mid-IR behind that in the optical band for 13 CLAGNs with strong mid-IR variability, where the tight correlation between the time lag and the bolometric luminosity ($\tau -L$) for CLAGNs roughly follows that found in the luminous QSOs.

arXiv comment18 pages, accepted in APJ

References in corpus (102)

• Astropy: A Community Python Package for Astronomy
• The Wide-field Infrared Survey Explorer (WISE): Mission Description and Initial On-orbit Performance
• The Astropy Project: Building an inclusive, open-science project and status of the v2.0 core package
• The slope of the black-hole mass versus velocity dispersion correlation
• The Man Behind the Curtain: X-rays Drive the UV through NIR Variability in the 2013 AGN Outburst in NGC 2617
• Hot Accretion Flows Around Black Holes
• A fundamental plane of black hole activity
• Nuclear Activity in Nearby Galaxies
• The All-Sky Automated Survey for Supernovae (ASAS-SN) Light Curve Server v1.0
• Revisiting the Unified Model of Active Galactic Nuclei
• Mid-Infrared Selection of AGN with the Wide-Field Infrared Survey Explorer. I. Characterizing WISE-Selected AGN in COSMOS
• AGN Black Hole Masses and Bolometric Luminosities
• Initial Performance of the NEOWISE Reactivation Mission
• On Uncertainties in Cross-Correlation Lags and the Reality of Wavelength-Dependent Continuum Lags in Active Galactic Nuclei
• The 105 month Swift-BAT all-sky hard X-ray survey
• Simultaneous X-ray/optical/UV snapshots of active galactic nuclei from XMM-Newton: spectral energy distributions for the reverberation mapped sample
• An Alternative Approach To Measuring Reverberation Lags in Active Galactic Nuclei
• 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
• BAT AGN Spectroscopic Survey I: Spectral Measurements, Derived Quantities, and AGN Demographics
• Modeling reverberation mapping data II: dynamical modeling of the Lick AGN Monitoring Project 2008 dataset
• The Mass Function of Active Black Holes in the Local Universe
• X-ray Spectral Properties of the BAT AGN Sample
• Changing look: from Compton-thick to Compton-thin, or the re-birth of fossil AGN
• Explaining changing-look AGN with state transition triggered by rapid mass accretion rate drop
• Reverberation Measurements of the Inner Radius of the Dust Torus in 17 Seyfert Galaxies
• Stellar Velocity Dispersion Measurements in High-Luminosity Quasar Hosts and Implications for the AGN Black Hole Mass Scale
• Discovery of 21 New Changing-look AGNs in Northern Sky
• AGN Type-casting: Mrk 590 No Longer Fits the Role
• Characterizing the Mid-IR Extragalactic Sky with WISE and SDSS
• The Radiative Efficiency of Hot Accretion Flows
• A Mid-IR Selected Changing-Look Quasar and Physical Scenarios for Abrupt AGN Fading
• Changing-Look Quasar Candidates: First Results from Follow-up Spectroscopy of Highly Optically Variable Quasars
• The ASAS-SN Catalog of Variable Stars III: Variables in the Southern TESS Continuous Viewing Zone
• Mid-infrared variability of changing-look AGN
• The hard X-ray spectral evolution in X-ray binaries and its application to constrain the black hole mass of ultraluminous X-ray sources
• The anti-correlation between the hard X-ray photon index and the Eddington ratio in LLAGNs
• 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
• A New Class of Changing-Look LINERs
• Reverberation Mapping of Optical Emission Lines in Five Active Galaxies
• Indicators of Intrinsic AGN Luminosity: a Multi-Wavelength Approach
• A candidate sub-parsec binary black hole in the Seyfert galaxy NGC 7674
• IC 751: a new changing-look AGN discovered by NuSTAR
• A search for changing-look AGN in the Grossan catalog
• The Close AGN Reference Survey (CARS) - What is causing Mrk1018's return to the shadows after 30 years?
• NGC 3065: A Certified LINER With Broad, Variable Balmer Lines
• Rapid Infrared Variability of Three Radio-loud Narrow-line Seyfert 1 Galaxies: A View from the Wide-field Infrared Survey Explorer
• Mid-IR Variability and Dust Reverberation Mapping of Low-$z$ Quasars. I. Data, Methods and Basic Results
• Broad Hbeta Emission-Line Variability in a Sample of 102 Local Active Galaxies
• Low-luminosity Active Galaxies and their Central Black Holes
• Reverberation Measurements of the Inner Radii of the Dust Tori in Quasars
• The NuSTAR view of reflection and absorption in NGC 7582
• Initial results from a systematic search for changing-look active galactic nuclei selected via mid-infrared variability
• Stratified disc wind models for the AGN broad-line region: ultraviolet, optical and X-ray properties
• Updating quasar bolometric luminosity corrections. II. Infrared bolometric corrections
• Detection of faint broad emission lines in type 2 AGN: II. On the measurement of the BH mass of type 2 AGN and the unified model
• NGC454: unveiling a new "changing look" AGN
• The Sloan Digital Sky Survey Reverberation Mapping Project: Accretion and Broad Emission Line Physics from a Hypervariable Quasar
• Reverberation Mapping of Changing-look Active Galactic Nucleus NGC 3516
• A rapid occultation event in NGC 3227
• The Landscape of Galaxies Harboring Changing-Look Active Galactic Nuclei in the Local Universe
• Black hole spin and size of the X-ray emitting region(s) in the Seyfert 1.5 galaxy ESO 362-G18
• The Eddington ratio-dependent changing look events in NGC 2992
• Two New "Turn-off" Changing-look Active Galactic nuclei and Implication on "Partially Obscured" AGNs
• Correlated X-ray/UV/optical variability and the nature of accretion disc in the bare Seyfert 1 galaxy Fairall~9
• Broad-line region structure and line profile variations in the changing look AGN HE1136-2304
• Broadband X-Ray Observations of the 2018 Outburst of the Changing-Look Active Galactic Nucleus NGC 1566
• Rapid Luminosity Decline and Subsequent Reformation of the Innermost Dust Distribution in the Changing-look AGN Mrk 590
• X-ray time lags in AGN: inverse-Compton scattering and spherical corona model
• Long Term Wind-Driven X-Ray Spectral Variability of NGC 1365 with Swift
• Modelling the X-ray polarimetric signatures of complex geometry: the case study of the "changing look" AGN NGC 1365
• Long-term and multi-wavelength evolution of a changing-look AGN Mrk 1018
• Parsec-scale radio morphology and variability of a changing-look AGN: the case of Mrk 590
• The post-maximum behaviour of the changing-look Seyfert galaxy NGC 1566
• Optical and X-ray discovery of the changing-look AGN IRAS23226-3843 showing extremely broad and double-peaked Balmer profiles
• WISE view of Narrow-Line Seyfert 1 galaxies: mid-infrared color and variability
• Simultaneous XMM-\textit{Newton} and HST-COS observation of 1H0419-577: II. Broadband spectral modeling of a variable Seyfert galaxy
• Short-Timescale monitoring of the X-ray, UV and broad double-peak emission line of the nucleus of NGC 1097
• The lively accretion disk in NGC 2992. I. Transient iron K emission lines in the high flux state
• The Kinematics of Quasar Broad Emission Line Regions Using a Disk-wind Model
• Dust Reverberation of 3C273: torus structure and lag -- luminosity relation
• Optical and near-infrared IFU spectroscopy of the nuclear region of the AGN-starburst galaxy NGC 7582
• Probing Nuclear and Circumnuclear Properties of NGC 6300 using X-ray Observations
• Host Galaxy Properties of Changing-look AGN Revealed in the MaNGA Survey
• Spectropolarimetry of the changing-look active galactic nucleus Mrk 1018
• Line profile and continuum variability in the very broad-line Seyfert galaxy Mrk 926
• A systematic search for changing-look quasars in SDSS-II using difference spectra
• A parsec-scale faint jet in the nearby changing-look Seyfert galaxy Mrk 590
• Exploring the spectral variability of the Seyfert 1.5 galaxy Markarian 530 with Suzaku
• A compact core-jet structure in the changing-look Seyfert NGC 2617
• A NICER Look at Strong X-ray Obscuration in the Seyfert-2 Galaxy NGC 4388
• A Systematic Survey for z < 0.04 Changing-Look AGNs
• FRAMEx II: Simultaneous X-ray and Radio Variability in Active Galactic Nuclei $-$ The Case of NGC 2992
• Dust Reverberation Mapping of Z229-15
• Dust Reverberation Mapping of Type 2 AGN NGC 2110 Realized with X-ray and 3-5 $\mu$m IR monitoring
• SkyMapper colours of Seyfert galaxies and Changing-Look AGN
• A close look at the well-known Seyfert galaxy: extended emission filaments in Mrk6
• Changing-look Seyfert galaxies with optical linear polarization measurements
• Multi-wavelenth monitoring of the changing-look AGN NGC 2617 during state changes
• A changing-look AGN to be probed by X-ray polarimetry
• Revisiting old (AGN) friends -- what's changed in their spectral looks

Cited by in corpus (11)

• Infrared Spectral Energy Distribution and Variability of Active Galactic Nuclei: Clues to the Structure of Circumnuclear Material
• Application of the disk instability model to all Quasi-Periodic Eruptions
• Velocity-resolved Reverberation Mapping of Changing-look Active Galactic Nucleus NGC~4151 During Outburst Stage: Evidence for Kinematics Evolution of Broad-line Region
• The rise and fall of the iron-strong nuclear transient PS16dtm
• The Past and Future of Mid-Infrared Studies of AGN
• Improving the selection of changing-look AGNs through multi-wavelength photometric variability
• SDSS1335+0728: The awakening of a $\sim 10^6{M}_{\odot }$ black hole
• Multiphase Gas Nature in the Sub-parsec Region of the Active Galactic Nuclei I: Dynamical Structures of Dusty and Dust-free Outflow
• Multiple Flares in the Changing-Look AGN NGC 5273
• The Physical Properties of Changing-look Blazars
• The Fermi-LAT view of the changing-look blazar OQ 334