Evolution of a Relativistic Outflow and X-ray Corona in the Extreme Changing-Look AGN 1ES 1927+654

Abstract

1ES 1927+654 is a paradigm-defying AGN and one of the most peculiar X-ray nuclear transients. In early 2018, this well-known AGN underwent a changing-look event, in which broad optical emission lines appeared and the optical flux increased. Yet, by July 2018, the X-ray flux had dropped by over two orders of magnitude, indicating a dramatic change to the inner accretion flow. With three years of observations with NICER, XMM-Newton, and NuSTAR, we present the X-ray evolution of 1ES 1927+654, which can be broken into three phases-(1) an early super-Eddington phase with rapid variability in X-ray luminosity and spectral parameters, (2) a stable super-Eddington phase at the peak X-ray luminosity, and (3) a steady decline back to the pre-outburst luminosity and spectral parameters. For the first time, we witnessed the formation of the X-ray corona, as the X-ray spectrum transitioned from thermally-dominated to primarily Comptonized. We also track the evolution of the prominent, broad 1 keV feature in the early X-ray spectra and show that this feature can be modeled with blueshifted reflection (z = -0.33) from a single-temperature blackbody irradiating spectrum using xillverTDE, a new flavor of the xillver models. Thus, we propose that the 1 keV feature could arise from reflected emission off the base of an optically thick outflow from a geometrically thick, super-Eddington inner accretion flow, connecting the inner accretion flow with outflows launched during extreme accretion events (e.g. tidal disruption events). Lastly, we compare 1ES 1927+654 to other nuclear transients and discuss applications of xillverTDE to super-Eddington accretors.

25 pages, 10 figures, accepted for publication in ApJ

References in corpus (47)

• HI4PI: A full-sky HI survey based on EBHIS and GASS
• BAT AGN Spectroscopic Survey - V. X-ray properties of the Swift/BAT 70-month AGN catalog
• 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
• The role of the reflection fraction in constraining black hole spin
• The Hard X-ray Spectral Slope as an Accretion-Rate Indicator in Radio-Quiet Active Galactic Nuclei
• An Empirical Background Model for the NICER X-ray Timing Instrument
• X-ray Quasi-Periodic Eruptions from two previously quiescent galaxies
• The destruction and recreation of the X-ray corona in a changing-look Active Galactic Nucleus
• Mid-infrared variability of changing-look AGN
• On the Iwasawa-Taniguchi effect of radio-quiet AGN
• Possible X-ray Quasi-Periodic Eruptions in a Tidal Disruption Event Candidate
• A possible mechanism for multiple changing look phenomenon in Active Galactic Nuclei
• GSN 069 -- A Tidal Disruption Near-Miss
• X-ray Quasi-periodic Eruptions driven by Star-Disc Collisions : Application to GSN069 and Probing the Spin of Massive Black Holes
• A 200-s Quasi-Periodicity Following the Tidal Disruption of a Star by a Dormant Black Hole
• Interacting Stellar EMRIs as Sources of Quasi-Periodic Eruptions in Galactic Nuclei
• Disc tearing: implications for black hole accretion and AGN variability
• Iron K$\alpha$ emission in type-I and type-II Active Galactic Nuclei
• Ultrafast Outflow in Tidal Disruption Event ASASSN-14li
• A self-lensing binary massive black hole interpretation of quasi-periodic eruptions
• The XMM-Newton view of AGN with intermediate mass black holes
• An Iron K Component to the Ultrafast Outflow in NGC 1313 X-1
• Self-Consistent Black Hole Accretion Spectral Models and the Forgotten Role of Coronal Comptonization of Reflection Emission
• Searching for Outflows in Ultraluminous X-ray Sources Through High-Resolution X-ray Spectroscopy
• Relativistic X-ray Reflection Models for Accreting Neutron Stars
• XMM-Newton campaign on the ultraluminous X-ray source NGC 247 ULX-1: outflows
• NuSTAR Observations of the Accreting Atolls GX 3+1, 4U 1702-429, 4U 0614+091, and 4U 1746-371
• Indecent Exposure in Seyfert 2 Galaxies: A Close Look
• The 450 days X-ray monitoring of the changing-look AGN 1ES 1927+654
• Polarization of changing-look quasars
• Frame-dragging, disk warping, jet precessing, and dipped X-ray lightcurve of Sw J1644+57
• Magnetic flux inversion in a peculiar changing look AGN
• Reflection Modeling of the Black Hole Binary 4U~1630$-$47: the Disk Density and Returning Radiation
• Radius Constraints from Reflection Modeling of Cygnus X-2 with NuSTAR and NICER
• HST unveils a compact mildly relativistic Broad Line Region in the candidate true type 2 NGC 3147
• The Nature of Soft Excess in ESO 362-G18 Revealed by XMM-Newton and NuSTAR Spectroscopy
• The Eddington ratio-dependent changing look events in NGC 2992
• NICER-NuSTAR Observations of the Neutron Star Low-Mass X-ray Binary 4U 1735-44
• NuSTAR observation of Ark 564 reveals the variation of coronal temperature with flux
• Distinct High Energy Cutoff Variation Patterns in Two Seyfert Galaxies
• Ejection-accretion connection in NLS1 AGN 1H 1934-063
• The chameleon on the branches: spectral state transition and dips in NGC 247 ULX-1
• An X-ray spectral study of the origin of reflection features in bare Seyfert 1 galaxy ESO 511--G030
• Relativistic X-ray reverberation from super-Eddington accretion flow
• The Origin of X-ray Emission in the Gamma-ray emitting Narrow-Line Seyfert 1 1H 0323+342
• A radio, optical, UV and X-ray view of the enigmatic changing look Active Galactic Nucleus 1ES~1927+654 from its pre- to post-flare states

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• Modified models of radiation pressure instability in application to 10, 10${}^5$, and 10${}^7$ $M_{\odot }$ accreting black holes
• HYPerluminous quasars at the Epoch of ReionizatION (HYPERION). A new regime for the X-ray nuclear properties of the first quasars
• Chandra, HST/STIS, NICER, Swift, and TESS Detail the Flare Evolution of the Repeating Nuclear Transient ASASSN-14ko
• A Case for a Binary Black Hole System Revealed via Quasi-Periodic Outflows
• X-ray Reverberation Mapping of Ark 564 using Gaussian Process Regression
• BASS-XL: X-ray variability properties of unobscured Active Galactic Nuclei
• TESS Shines Light on the Origin of the Ambiguous Nuclear Transient ASASSN-18el
• MRI turbulence in vertically stratified accretion discs at large magnetic Prandtl numbers
• Modeling Multiple X-Ray Reflection in Super-Eddington Winds
• An Extremely Luminous Flare Recorded from a Supermassive Black Hole
• X-ray Unveiling Events in a z~1.6 Active Galactic Nucleus in the 7 Ms Chandra Deep Field-South
• Unveiling the Cosmic Dance of Repeated Nuclear Transient ASASSN-14ko: Insights from Multiwavelength Observations
• Probing extreme black-hole outflows on short timescales via high spectral-resolution X-ray imagers
• A supermassive black hole under the radar: Repeating X-ray variability in a Seyfert galaxy