Tracking the state transitions in changing-look active galactic nuclei through their polarized-light echoes

Abstract

Context: Variations in the mass accretion rate appear to be responsible for the rapid transitions in spectral type that are observed in increasingly more active galactic nuclei (AGNs). These objects are now labeled "changing-look" AGNs and are key objects for understanding the physics of accretion onto supermassive black holes. Aims: We aim to complement the analysis and interpretation of changing-look AGNs by modeling the polarization variations that can be observed, in particular, polarized-light echoes. Methods: We built a complex and representative model of an AGN and its host galaxy and ran radiative transfer simulations to obtain realistic time-dependent polarization signatures of changing-look objects. Based on actual data, we allowed the system to become several times fainter or brighter within a few years, assuming a rapid change in accretion rate. Results: We obtain time-dependent polarization signatures of distant high-luminosity (quasars) and nearby low-luminosity (Seyferts) changing-look AGNs for a representative set of inclinations. We predict the evolution of the continuum polarization for future polarimetric campaigns with the goal to better understand the physics at work in these objects. We also investigate highly inclined AGNs that experience strong accretion rate variations without appearing to change state. We apply our modeling to Mrk 1018, the best-documented case of a changing-look AGN, and predict a variation in its polarization after the recent dimming of its continuum.

arXiv comment13 pages, 7 figures, accepted for publication in Astronomy & Astrophysics

References in corpus (52)

• The Host Galaxies of AGN
• The Man Behind the Curtain: X-rays Drive the UV through NIR Variability in the 2013 AGN Outburst in NGC 2617
• AGN Dusty Tori: II. Observational Implications of Clumpiness
• AGN Dusty Tori: I. Handling of Clumpy Media
• The Discovery of the First "Changing Look" Quasar: New Insights into the Physics & Phenomenology of AGN
• A Systematic Search for Changing-Look Quasars in SDSS
• Suzaku observations of 'bare' active galactic nuclei
• Determining Inclinations of Active Galactic Nuclei Via Their Narrow-Line Region Kinematics - I. Observational Results
• The origin of the Broad Line Region in Active Galactic Nuclei
• Spatially resolved rotation of the broad-line region of a quasar at sub-parsec scale
• Explaining changing-look AGN with state transition triggered by rapid mass accretion rate drop
• Jet directions in Seyfert galaxies
• The WISE AGN Catalog
• Discovery of 21 New Changing-look AGNs in Northern Sky
• AGN Type-casting: Mrk 590 No Longer Fits the Role
• Evolution of Broad-line Emission from Active Galactic Nuclei
• 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
• Type II Quasars from the Sloan Digital Sky Survey: V. Imaging host galaxies with the Hubble Space Telescope
• iPTF Discovery of the Rapid "Turn On" of a Luminous Quasar
• Modeling optical and UV polarization of AGNs I. Imprints of individual scattering regions
• Candidate Type II Quasars from the SDSS: III. Spectropolarimetry Reveals Hidden Type I Nuclei
• The Close AGN Reference Survey (CARS) - Mrk 1018 returns to the shadows after 30 years as a Seyfert 1
• The Toroidal Obscuration of Active Galactic Nuclei
• Understanding extreme quasar optical variability with CRTS: II. Changing-state quasars
• Modeling optical and UV polarization of AGNs II. Polarization imaging and complex reprocessing
• The Close AGN Reference Survey (CARS) - What is causing Mrk1018's return to the shadows after 30 years?
• Are there reliable methods to estimate the nuclear orientation of Seyfert galaxies?
• Modeling optical and UV polarization of AGNs III. From uniform-density to clumpy regions
• Polarization of changing-look quasars
• Long-term optical spectral monitoring of a changing-look AGN NGC 3516 I: Continuum and broad-line flux variability
• Inclinations and black hole masses of Seyfert 1 galaxies
• Does the obscured AGN fraction really depend on luminosity?
• HST unveils a compact mildly relativistic Broad Line Region in the candidate true type 2 NGC 3147
• Identification of SDSSJ141324.27+530527.0 as A New "Changing-Look" Quasar with a "Turn-on" Transition
• Modeling optical and UV polarization of AGNs V. Dilution by interstellar polarization and the host galaxy
• Variability in Spectropolarimetric properties of Sy 1.5 galaxy Mrk 6
• Determining Inclinations of Active Galactic Nuclei Via Their Narrow-Line Region Kinematics - II. Correlation With Observed Properties
• Recoiling supermassive black hole in changing-look AGN Mrk 1018
• Polarization of the changing-look quasar J1011+5442
• Discovery of Polarization Reverberation in NGC 4151
• AGN obscuration from winds: from dusty infrared-driven to warm and X-ray photoionized
• HST NICMOS Observations of the Polarization of NGC 1068
• A deep X-ray view of the bare AGN Ark 120. I. Revealing the Soft X-ray Line Emission
• The Close AGN Reference Survey (CARS): Mrk 1018 halts dimming and experiences strong short-term variability
• UV Imaging Polarimetry of the Seyfert 2 Galaxy Mrk 3
• Unveiling the physics behind the spectral variations of "changing-look" quasars with optical polarimetry
• Polarization Insights for Active Galactic Nuclei
• Spectropolarimetric monitoring of active galaxy 3C390.3 with 6m telescope SAO RAS in the period 2009-2014
• Exploring the inner parsecs of Active Galactic Nuclei using near-infrared high resolution polarimetric simulations with MontAGN

Cited by in corpus (3)

• Spectropolarimetry of the changing-look active galactic nucleus Mrk 1018
• The optically elusive, changing-look active nucleus in NGC 4156
• Optical polarization of stellar-fed active and quiescent supermassive black holes