Understanding extreme quasar optical variability with CRTS: II. Changing-state quasars

Abstract

We present the results of a systematic search for quasars in the Catalina Real-time Transient Survey exhibiting both strong photometric and spectroscopic variability over a decadal baseline. We identify 73 sources with specific patterns of optical and mid-IR photometric behavior and a defined spectroscopic change. These "Changing-State" quasars (CSQs) form a higher luminosity sample to complement existing sets of "Changing-Look" AGN and quasars in the literature. The CSQs (by selection) exhibit larger photometric variability than the CLQs. The spectroscopic variability is marginally stronger in the CSQs than CLQs as defined by the change in H$\beta$/[OIII] ratio. We find 36 sources with declining H$\beta$ flux, 37 sources with increasing H$\beta$ flux and discover seven sources with $z>0.8$, further extending the redshift arm. Our CSQ sample compares to the literature CLQ objects in similar distributions of H$\beta$ flux ratios and differential Eddington ratios between high (bright) and low (dim) states. Taken as a whole, we find that this population of extreme varying quasars is associated with changes in the Eddington ratio and the timescales imply cooling/heating fronts propagating through the disk.

arXiv comment43 pages, 22 figures, submitted

References in corpus (60)

• Maps of Dust IR Emission for Use in Estimation of Reddening and CMBR Foregrounds
• Measuring Reddening with SDSS Stellar Spectra and Recalibrating SFD
• The Zwicky Transient Facility: System Overview, Performance, and First Results
• The Man Behind the Curtain: X-rays Drive the UV through NIR Variability in the 2013 AGN Outburst in NGC 2617
• A Catalog of Quasar Properties from SDSS DR7
• First Results from the Catalina Real-time Transient Survey
• The Zwicky Transient Facility: Science Objectives
• Are the Variations in Quasar Optical Flux Driven by Thermal Fluctuations?
• The Fourteenth Data Release of the Sloan Digital Sky Survey: First Spectroscopic Data from the extended Baryon Oscillation Spectroscopic Survey and from the second phase of the Apache Point Observatory Galactic Evolution Experiment
• Studies in Astronomical Time Series Analysis. VI. Bayesian Block Representations
• Accretion disc viscosity: how big is alpha?
• The Catalina Surveys Periodic Variable Star Catalog
• Seven-Year Wilkinson Microwave Anisotropy Probe (WMAP) Observations: Galactic Foreground Emission
• The Discovery of the First "Changing Look" Quasar: New Insights into the Physics & Phenomenology of AGN
• A possible close supermassive black-hole binary in a quasar with optical periodicity
• Is Quasar Optical Variability a Damped Random Walk?
• The 5th edition of the Roma-BZCAT. A short presentation
• A Systematic Search for Changing-Look Quasars in SDSS
• A systematic search for close supermassive black hole binaries in the Catalina Real-Time Transient Survey
• Sustained Magnetorotational Turbulence in Local Simulations of Stratified Disks with Zero Net Magnetic Flux
• 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
• Probing the Outer Galactic halo with RR Lyrae from the Catalina Surveys
• The WISE AGN Catalog
• Discovery of 21 New Changing-look AGNs in Northern Sky
• AGN Type-casting: Mrk 590 No Longer Fits the Role
• 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
• Towards an Understanding of Changing-Look Quasars: An Archival Spectroscopic Search in SDSS
• Mid-infrared variability of changing-look AGN
• An X-shooter composite of bright 1 < z < 2 quasars from UV to infrared
• Are the Variability Properties of the Kepler AGN Light Curves Consistent with a Damped Random Walk?
• iPTF Discovery of the Rapid "Turn On" of a Luminous Quasar
• Exploring the Variable Sky with LINEAR. III. Classification of Periodic Light Curves
• A new physical interpretation of optical and infrared variability in quasars
• Understanding extreme quasar optical variability with CRTS: I. Major AGN flares
• The Kepler Light Curves of AGN: A Detailed Analysis
• Seyfert 1 mutation of the classical Seyfert 2 nucleus NGC 7582
• Turbulent Stresses in Local Simulations of Radiation-Dominated Accretion Disks, and the Possibility of the LIghtman-Eardley Instability
• A novel variability-based method for quasar selection: evidence for a rest frame ~54 day characteristic timescale
• A Revised Calibration of the Virial Mass Estimator for Black Holes in Active Galaxies Based on Single-epoch H$\beta$ Spectra
• NGC 3065: A Certified LINER With Broad, Variable Balmer Lines
• Virial Black Hole Mass Estimates for 280,000 AGNs from the SDSS Broad-Band Photometry and Single Epoch Spectra
• Broad Hbeta Emission-Line Variability in a Sample of 102 Local Active Galaxies
• The detection and X-ray view of the changing look AGN HE 1136-2304
• Slow blue nuclear hypervariables in PanSTARRS-1
• Polarization of changing-look quasars
• The NuSTAR view of reflection and absorption in NGC 7582
• Improved AGN light curve analysis with the z-transformed discrete correlation function
• The Multi-Layer Variable Absorbers in NGC 1365 Revealed by XMM-Newton and NuSTAR
• Recoiling supermassive black hole in changing-look AGN Mrk 1018
• Polarization of the changing-look quasar J1011+5442
• A Study of Outflows in Luminous Quasars at Redshift $\sim 0.4-0.8$
• Unveiling the physics behind the spectral variations of "changing-look" quasars with optical polarimetry
• Gemini Imaging of the Host Galaxies of Changing-Look Quasars
• Extreme Variability in a Broad Absorption Line Quasar
• An Unobscured type II quasar candidate: SDSS J012032.19-005501.9
• Mechanism of the Changing Look phenomenon in Active Galactic Nuclei
• Results of a systematic search for outburst events in 1.4 million galaxies
• The 'Big Dipper': The nature of the extreme variability of the AGN SDSS J2232-0806

Cited by in corpus (64)

• The Automatic Learning for the Rapid Classification of Events (ALeRCE) Alert Broker
• Aligning Nuclear Cluster Orbits with an Active Galactic Nucleus Accretion Disk
• Improving Damped Random Walk parameters for SDSS Stripe 82 Quasars with Pan-STARRS1
• Science objectives of the Einstein Probe mission
• Mid-InfraRed Outburst in Nearby Galaxies (MIRONG) I: Sample Selection and Characterization
• Binary Black Hole Merger Rates in AGN Disks versus Nuclear Star Clusters: Loud beats Quiet
• A Family Tree of Optical Transients from Narrow-Line Seyfert 1 Galaxies
• Magnetically Dominated Disks in Tidal Disruption Events and Quasi-Periodic Eruptions
• Modified models of radiation pressure instability in application to 10, 10${}^5$, and 10${}^7$ $M_{\odot }$ accreting black holes
• Exploring Changing-look Active Galactic Nuclei with the Sloan Digital Sky Survey V: First Year Results
• Second Data Release of the All-sky NOIRLab Source Catalog
• AT 2017gbl: a dust obscured TDE candidate in a luminous infrared galaxy
• Searching for changing-state AGNs in massive datasets -- I: applying deep learning and anomaly detection techniques to find AGNs with anomalous variability behaviours
• Changing-look active galactic nuclei: close binaries of supermassive black holes in action
• 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
• Extreme Variability and Episodic Lifetime of Quasars
• Supermassive Black Hole and Broad-line Region in NGC~5548: Results from Five-season Reverberation Mapping
• The rise and fall of the iron-strong nuclear transient PS16dtm
• The Eddington ratio-dependent changing look events in NGC 2992
• The Near and Mid-infrared photometric properties of known redshift $z\ge 5$ Quasars
• Starfall: A heavy rain of stars in 'turning on' AGN
• High-redshift Extreme Variability Quasars from Sloan Digital Sky Survey Multi-Epoch Spectroscopy
• WISE view of changing-look AGNs: evidence for a transitional stage of AGNs
• A flare in the optical spotted in the changing-look Seyfert NGC 3516
• Long-term and multi-wavelength evolution of a changing-look AGN Mrk 1018
• AT 2021loi: A Bowen Fluorescence Flare with a Rebrightening Episode, Occurring in a Previously-Known AGN
• Discovery of the luminous X-ray ignition eRASSt J234402.9$-$352640; I. Tidal disruption event or a rapid increase in accretion in an active galactic nucleus?
• NuSTAR Observations of AGN with Low Observed X-ray to [OIII] Luminosity Ratios: Heavily Obscured AGN or Turned-Off AGN?
• Optical and X-ray discovery of the changing-look AGN IRAS23226-3843 showing extremely broad and double-peaked Balmer profiles
• Improving the selection of changing-look AGNs through multi-wavelength photometric variability
• The Type 1 and Type 2 AGN dichotomy according to their ZTF optical variability
• Narrow Fe-K$\alpha$ Reverberation Mapping Unveils the Deactivated Broad-Line Region in a Changing-Look Active Galactic Nucleus
• SDSS1335+0728: The awakening of a $\sim 10^6{M}_{\odot }$ black hole
• 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
• Multiwavelength observations of the extraordinary accretion event AT2021lwx
• Local Active Galactic Nuclei with Large Broad-Hα Variability Reside in Red Galaxies
• The outburst of the changing-look AGN IRAS23226-3843 in 2019
• Characterization of Optical Light Curves of Extreme Variability Quasars Over a ~16-yr Baseline
• Ensemble power spectral density of SDSS quasars in UV/optical bands
• Behaviour of the MgII 2798AA Line Over the Full Range of AGN Variability
• Detailed accretion history of the supermassive black hole in NGC 5972 over the past $\gtrsim$10${}^4$ years through the extended emission line region
• Multiple Flares in the Changing-Look AGN NGC 5273
• Modeling changing-look (CL) AGN phenomenon in 1D using accretion disk instabilities
• Dusty plasma in active galactic nuclei
• The Fermi-LAT view of the changing-look blazar OQ 334
• LIGO tells us LINERs are not optically thick RIAFs
• Tracing the AGN/X-ray Binary Analogy with Light Curves of Individual Changing-Look AGN
• B3\,0749+460A: A New "Changing-Look" Active Galactic Nucleus Associated with X-ray Spectral Slope Variations
• Suspended and restored activities of A Nearby Super Massive Black Hole
• Tracking the state transitions in changing-look active galactic nuclei through their polarized-light echoes
• Discovery of a new extreme changing-state quasar with 4 mag variation, SDSS J125809.31+351943.0
• Examining AGN UV/Optical Variability Beyond the Simple Damped Random Walk. II. Insights from 22 Years Observations of SDSS, PS1 and ZTF
• Contribution of Flares from Tidal Disruption of Stars to high-redshift AGN
• Winds of change: the nuclear and galaxy-scale outflows and the X-ray variability of 2MASS 0918+2117
• Extreme scale height variations and nozzle shocks in warped disks
• The relation between quasars' optical spectra and variability
• The Variability of the Broad Line Profiles of SDSS J1430+2303
• Scalable and Robust Multiband Modeling of AGN Light Curves in Rubin-LSST
• X-ray spectral shape variations in changing-look Seyfert galaxy SDSSJ155258+273728
• Identifying Changing-Look AGN Transitions in Light Curve Data with the Zwicky Transient Facility
• 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
• Characterizing Some Gaia Alerts with LAMOST and SDSS