Finding of a population of active galactic nuclei showing a significant luminosity decline in the past $\sim 10^{3-4}$ yrs

Abstract

Recent observations have revealed an interesting active galactic nuclei (AGN) subclass that shows strong activity at large scales ($\sim 1$ kpc) but weaker at small scales ($<10$ pc), suggesting a strong change in the mass accretion rate of the central engine in the past $10^{3-4}$ yr. We systematically search for such declining or fading AGN by cross-matching the SDSS type-1 AGN catalog at $z<0.4$, covering the [OIII]$\lambda 5007$ emission line which is a tracer for the narrow-line region (NLR) emission, with the WISE mid-infrared (MIR) catalog covering the emissions from the dusty tori. Out of the 7,653 sources, we found 57 AGN whose bolometric luminosities estimated from the MIR band are at least one order of magnitude fainter than those estimated from the [OIII]$\lambda 5007$ emission line. This luminosity declining AGN candidate population shows four important properties: 1) the past AGN activity estimated from the [OIII]$\lambda 5007$ line reaches around the Eddington-limit, 2) more than 30% of the luminosity declining AGN candidates show a large absolute variability of $\Delta W1>0.45$ mag in the previous $\sim 10$ yr at the WISE 3.4 $\mu$m band, 3) the median ratio of $\log$([NII]$\lambda 6584/\mathrm{H}\alpha \lambda 6563)=-0.52$, suggesting a lower gas metallicity and/or higher ionization parameter compared to other AGN populations. 4) the second epoch spectra of the population indicate a spectral type change for 15% of the sources. This population provides insights on the possible connection between the luminosity decline which started $\sim 10^{3-4}$ yr ago and the decline in the recent $10$ yr.

21 pages, 10 figures, 2 tables (1 MRT), accepted for publication in ApJ

References in corpus (43)

• A luminous quasar at a redshift of z = 7.085
• An Observational Determination of the Bolometric Quasar Luminosity Function
• The Mass-Metallicity Relation at z~2
• Initial Performance of the NEOWISE Reactivation Mission
• An ultra-luminous quasar with a twelve-billion-solar-mass black hole at redshift 6.30
• Modeling the Time Variability of SDSS Stripe 82 Quasars as a Damped Random Walk
• A Luminous Quasar at Redshift 7.642
• A Global Three Dimensional Radiation Magneto-hydrodynamic Simulation of Super-Eddington Accretion Disks
• The Discovery of the First "Changing Look" Quasar: New Insights into the Physics & Phenomenology of AGN
• On the X-ray, optical emission line and black hole mass properties of local Seyfert galaxies
• The Last of FIRST: The Final Catalog and Source Identifications
• The WISE AGN Catalog
• Reverberation Measurements of the Inner Radius of the Dust Torus in 17 Seyfert Galaxies
• Resolving the obscuring torus in NGC 1068 with the power of infrared interferometry: Revealing the inner funnel of dust
• Global simulations of axisymmetric radiative black hole accretion disks in general relativity with a sub-grid magnetic dynamo
• The Infrared Nuclear Emission of Seyfert Galaxies on Parsec Scales: Testing the Clumpy Torus models
• Mid-infrared variability of changing-look AGN
• Optical variability of AGN in the PTF/iPTF survey
• Extremely Red Quasars in BOSS
• On the difference of torus geometry between hidden and non-hidden broad line active galactic nuclei
• The Complete Infrared View of Active Galactic Nuclei from the 70-month Swift/BAT Catalog
• Integral field spectroscopy of nearby QSOs: I. ENLR size-luminosity relation, ongoing star formation & resolved gas-phase metallicities
• Fading AGN Candidates: AGN Histories and Outflow Signatures
• Is there an upper limit to black hole masses?
• The Limited Impact of Outflows: Integral-Field Spectroscopy of 20 Local AGNs
• SDSS-IV MaNGA: Identification of active galactic nuclei in optical integral field unit surveys
• A sample of Seyfert-2 galaxies with ultra-luminous galaxy-wide NLRs -- Quasar light echos?
• Gemini Imaging of Mid-IR Emission from the Nuclear Region of Centaurus A
• Detecting and Characterizing Young Quasars II: Four Quasars at $z\sim 6$ with Lifetimes $<10^4$ years
• The Infrared Emission from the Narrow Line Region
• Dwarf AGNs from Optical Variability for the Origins of Seeds (DAVOS): Insights from the Dark Energy Survey Deep Fields
• Properties of AGN Multiband Optical Variability in the HSC SSP Transient Survey
• A 100 kpc nebula associated with the "Teacup" fading quasar
• NuSTAR Observations of AGN with Low Observed X-ray to [OIII] Luminosity Ratios: Heavily Obscured AGN or Turned-Off AGN?
• Active Galactic Nuclei with a Low-Metallicity Narrow-Line Region
• Hypercubes of AGN Tori (HYPERCAT) -- I. Models and Image Morphology
• Cooling timescale of dust tori in dying active galactic nuclei
• A systematic search for changing-look quasars in SDSS-II using difference spectra
• Detailed accretion history of the supermassive black hole in NGC 5972 over the past $\gtrsim$10${}^4$ years through the extended emission line region
• Hypercubes of AGN Tori (HYPERCAT) -- II. Resolving the Torus with Extremely Large Telescopes
• Discovery of a strong ionized-gas outflow in an AKARI-selected Ultra-luminous Infrared Galaxy at z = 0.5
• NuSTAR hard X-ray data and Gemini 3D spectra reveal powerful AGN and outflow histories in two low-redshift Lyman-$\alpha$ blobs
• NuSTAR Non-detection of a Faint Active Galactic Nucleus in an Ultraluminous IR Galaxy with Kpc-scale Fast Wind

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