Live to die another day: the rebrightening of AT2018fyk as a repeating partial tidal disruption event

Abstract

Stars that interact with supermassive black holes (SMBHs) can either be completely or partially destroyed by tides. In a partial tidal disruption event (TDE) the high-density core of the star remains intact, and the low-density, outer envelope of the star is stripped and feeds a luminous accretion episode. The TDE AT2018fyk, with an inferred black hole mass of $10^{7.7\pm 0.4}$ M${}_{\odot }$, experienced an extreme dimming event at X-ray (factor of $>$6000) and UV (factor $\sim$15) wavelengths $\sim$500--600 days after discovery. Here we report on the re-emergence of these emission components roughly 1200 days after discovery. We find that the source properties are similar to those of the pre-dimming accretion state, suggesting that the accretion flow was rejuvenated to a similar state. We propose that a repeating partial TDE, where the partially disrupted star is on a $\sim 1200$ day orbit about the SMBH and is periodically stripped of mass during each pericenter passage, powers its unique lightcurve. This scenario provides a plausible explanation for AT2018fyk's overall properties, including the rapid dimming event and the rebrightening at late times. We also provide testable predictions for the behavior of the accretion flow in the future: if the second encounter was also a partial disruption then we predict another strong dimming event around day 1800 (August 2023), and a subsequent rebrightening around day 2400 (March 2025). This source provides strong evidence of the partial disruption of a star by a SMBH.

ApJ Letters, accepted for publication

References in corpus (39)

• The Host Galaxies and Classification of Active Galactic Nuclei
• Improving the full spectrum fitting method: accurate convolution with Gauss-Hermite functions
• The eROSITA X-ray telescope on SRG
• The MUSE second-generation VLT instrument
• Evolutionary Stellar Population Synthesis with MILES. Part I: The Base Models and a New Line Index System
• The SRG X-ray orbital observatory, its telescopes and first scientific results
• The eROSITA Final Equatorial Depth Survey (eFEDS): The X-ray catalog
• An Empirical Background Model for the NICER X-ray Timing Instrument
• X-ray Quasi-Periodic Eruptions from two previously quiescent galaxies
• X-ray Brightening and UV Fading of Tidal Disruption Event ASASSN-15oi
• Gaia Photometric Science Alerts
• ASASSN-14ko is a Periodic Nuclear Transient in ESO 253-G003
• GSN 069 -- A Tidal Disruption Near-Miss
• The AMUSING++ Nearby Galaxy Compilation: I. Full Sample Characterization and Galactic--Scale Outflows Selection
• Infrared Echoes of Optical Tidal Disruption Events: ~1% Dust Covering Factor or Less at sub-parsec Scale
• Tidal disruptions by rotating black holes: effects of spin and impact parameter
• Host galaxy properties of quasi-periodically erupting X-ray sources
• Tidal disruption events from supermassive black hole binaries
• Stellar Tidal Disruption Events with Abundances and Realistic Structures (STARS): Library of Fallback Rates
• Rapid accretion state transitions following the tidal disruption event AT2018fyk
• Ultraviolet and X-ray variability of active galactic nuclei with Swift
• Tidal disruption events: the role of stellar spin
• Relativistic effects on tidal disruption kicks of solitary stars
• The Tidal Disruption Event AT2021ehb: Evidence of Relativistic Disk Reflection, and Rapid Evolution of the Disk-Corona System
• Evidence for a Compact Object in the Aftermath of the Extra-Galactic Transient AT2018cow
• Fallback Rates from Partial Tidal Disruption Events
• Fainter harder brighter softer: a correlation between ${\alpha }_{\mathrm{ox}}$ , X-ray spectral state and Eddington ratio in tidal disruption events
• Rapid late-time X-ray brightening of the tidal disruption event OGLE16aaa
• Fourteen new eclipsing white dwarf plus main-sequence binaries from the SDSS and Catalina surveys
• The White Dwarf Binary Pathways Survey IV: Three close white dwarf binaries with G-type secondary stars
• Extreme ultra-soft X-ray variability in an eROSITA observation of the Narrow-Line Seyfert 1 Galaxy 1H 0707-495
• Tidal disruptions of main sequence stars -- IV. Relativistic effects and dependence on black hole mass
• The Eccentric Nature of Eccentric Tidal Disruption Events
• On the impact of relativistic gravity on the rate of tidal disruption events
• Spectropolarimetry of the tidal disruption event AT 2019qiz: a quasispherical reprocessing layer
• Compact Object Candidates with K/M-dwarf Companions from LAMOST Low-resolution Survey
• A White Dwarf-Main Sequence Binary Unveiled by Time-Domain Observations from LAMOST and TESS
• XMM-Newton detection of soft time lags in the TDE candidate AT 2018fyk
• Using the Hills Mechanism to Generate Repeating Partial Tidal Disruption Events and ASASSN-14ko

Cited by in corpus (35)

• Repeating tidal disruptions in GSN 069: Long-term evolution and constraints on quasi-periodic eruptions' models
• Unstable Mass Transfer from a Main-Sequence Star to a Supermassive Black Hole and Quasi-Periodic Eruptions
• X-ray eruptions every 22 days from the nucleus of a nearby galaxy
• Monthly quasi-periodic eruptions from repeated stellar disruption by a massive black hole
• The unluckiest star: A spectroscopically confirmed repeated partial tidal disruption event AT 2022dbl
• A Case for a Binary Black Hole System Revealed via Quasi-Periodic Outflows
• Rapid evolution of the recurrence time in the repeating partial tidal disruption event eRASSt J045650.3-203750
• The population of tidal disruption events discovered with eROSITA
• Partial Tidal Disruption of Main-Sequence Stars by Intermediate-Mass Black Holes
• Partial stellar tidal disruption events and their rates
• Recurring tidal disruption events a decade apart in IRAS F01004-2237
• Alive but Barely Kicking: News from 3+ years of Swift and XMM-Newton X-ray Monitoring of Quasi-Periodic Eruptions from eRO-QPE1
• SDSS1335+0728: The awakening of a $\sim 10^6{M}_{\odot }$ black hole
• Dissonance in harmony: The UV/optical periodic outbursts of ASASSN-14ko exhibit repeated bumps and rebrightenings
• Repeating Partial Tidal Encounters of Sun-like Stars Leading to their Complete Disruption
• Fate of the remnant in tidal stripping event: repeating and non-repeating
• TESS Shines Light on the Origin of the Ambiguous Nuclear Transient ASASSN-18el
• Flaires: A Comprehensive Catalog of Dust-Echo-like Infrared Flares
• AT2018fyk: Candidate Tidal Disruption Event by a (Super)massive Black Hole Binary
• Binary Stars Approaching Supermassive Black Holes: Tidal Break-up, Double Stellar Disruptions and Stellar Collision
• Three-dimensional simulations of the magnetorotational instability in eccentric disks
• Tidal disruption event associated with the quasi-periodic eruptions from GSN 069: Possible disruption of a common envelope
• Early Identification of Optical Tidal Disruption Events: A science module for the Fink broker
• X-ray Unveiling Events in a z~1.6 Active Galactic Nucleus in the 7 Ms Chandra Deep Field-South
• Partial Tidal Disruption Events by Intermediate-mass Black Holes in Supermassive and Intermediate-mass Black Hole Binaries
• Unveiling the Cosmic Dance of Repeated Nuclear Transient ASASSN-14ko: Insights from Multiwavelength Observations
• Repeating X-ray bursts: Interaction between a neutron star and clumps partially disrupted from a planet
• MUSE IFU observations of galaxies hosting Tidal Disruption Events
• Rapid onset of a Comptonisation zone in the repeating tidal disruption event XMMSL2 J140446.9-251135
• Evolution of accretion disc-corona in the TDE Candidate AT 2019avd
• Precursors in tidal disruption events: repeating, fast, and AGN-hosted TDEs
• Irregular Repeating Tidal Disruption Events due to Diffusive Tides
• Rate of Repeating Tidal Disruption Events with 5--19 years interval
• Hyperluminous Supersoft X-Ray Sources in the Chandra Catalog
• Tidal capture and repeating partial tidal disruption events of giant stars