A possible 250-second X-ray quasi-periodicity in the fast blue optical transient AT2018cow

Abstract

The fast blue optical transients (FBOTs) are a new population of extragalactic transients of unclear physical origin. A variety of mechanisms have been proposed including failed supernova explosion, shock interaction with a dense medium, young magnetar, accretion onto a compact object, and stellar tidal disruption event, but none is conclusive. Here we report the discovery of a possible X-ray quasi-periodicity signal with a period of $\sim$250 second (at a significance level of 99.76%) in the brightest FBOT AT2018cow through the analysis of XMM-Newton/PN data. The signal is independently detected at the same frequency in the average power density spectrum from data taken from the Swift telescope, with observations covering from 6 to 37 days after the optical discovery, though the significance level is lower (94.26%). This suggests that the QPO frequency may be stable over at least 1.1$\times$ 10${}^4$ cycles. Assuming the $\sim$250 second QPO to be a scaled-down analogue of that typically seen in stellar mass black holes, a black hole mass of $\sim 10^3-10^5$ solar masses could be inferred. The overall X-ray luminosity evolution could be modeled with the stellar tidal disruption by a black hole of $\sim 10^4$ solar masses, providing a viable mechanism to produce AT2018cow. Our findings suggest that other bright FBOTs may also harbor intermediate-mass black holes.

arXiv comment18 pages, 10 figures. Accepted for publication in Research in Astronomy and Astrophysics

References in corpus (49)

• X-ray Properties of Black-Hole Binaries
• Intermediate-Mass Black Holes
• Science with the space-based interferometer LISA. V: Extreme mass-ratio inspirals
• Hydrodynamical Simulations to Determine the Feeding Rate of Black Holes by the Tidal Disruption of Stars: The Importance of the Impact Parameter and Stellar Structure
• An Intermediate-mass Black Hole of Over 500 Solar Masses in the Galaxy ESO 243-49
• Measuring the broadband power spectra of active galactic nuclei with RXTE
• The ABC of low-frequency quasi-periodic oscillations in Black-Hole Candidates: analogies with Z-sources
• A review of quasi-periodic oscillations from black hole X-ray binaries: observation and theory
• Rapidly-Evolving and Luminous Transients from Pan-STARRS1
• An embedded X-ray source shines through the aspherical AT2018cow: revealing the inner workings of the most luminous fast-evolving optical transients
• Weighing Black Holes using Tidal Disruption Events
• Gemini and Hubble Space Telescope Evidence for an Intermediate Mass Black Hole in omega Centauri
• The Cow: discovery of a luminous, hot and rapidly evolving transient
• The Fast, Luminous Ultraviolet Transient AT2018cow: Extreme Supernova, or Disruption of a Star by an Intermediate-Mass Black Hole?
• Mass Fall-back and Accretion in the Central Engine of Gamma-Ray Bursts
• A Bayesian test for periodic signals in red noise
• High-Frequency Quasi-Periodic Oscillations in black-hole binaries
• Rapidly evolving transients in the Dark Energy Survey
• The faint "heartbeats" of IGR J17091-3624: an exceptional black-hole candidate
• Determination of Black Hole Masses in Galactic Black Hole Binaries using Scaling of Spectral and Variability Characteristics
• A luminous X-ray outburst from an intermediate-mass black hole in an off-centre star cluster
• Tracing the power-law component in the energy spectrum of black hole candidates as a function of the QPO frequency
• AT2018cow: a luminous millimeter transient
• The star ingesting luminosity of intermediate mass black holes in globular clusters
• A 200-s Quasi-Periodicity Following the Tidal Disruption of a Star by a Dormant Black Hole
• Measuring mass and angular momentum of black holes with high-frequency quasi-periodic oscillations
• Partial Stellar Disruption by a Supermassive Black Hole: Is the Lightcurve Really Proportional to $t^{-9/4}$?
• Black Hole Mass of the Ultraluminous X-ray source M82 X-1
• A likely decade-long sustained tidal disruption event
• Swift spectra of AT2018cow: A White Dwarf Tidal Disruption Event?
• New class of low frequency QPOs: signature of nuclear burning or accretion disk instabilities?
• Evidence for an Intermediate Mass Black Hole in NGC 5408 X-1
• A Remarkably Loud Quasi-Periodicity after a Star is Disrupted by a Massive Black Hole
• X-ray Swift observations of SN 2018cow
• On the Diversity of Fallback Rates from Tidal Disruption Events with Accurate Stellar Structure
• Evidence for a Compact Object in the Aftermath of the Extra-Galactic Transient AT2018cow
• Tidal Disruption of a Main-Sequence Star by an Intermediate-Mass Black Hole: A Bright Decade
• Universal scaling of the 3:2 twin-peak quasi-periodic oscillation frequencies with black hole mass and spin revisited
• A Blast from the Pasture: Studying the environment of AT 2018cow with MUSE
• The nearby luminous transient AT2018cow: a magnetar formed in a sub-relativistically expanding non-jetted explosion
• Evidence for High-Frequency QPOs with a 3:2 Frequency Ratio from a 5000 Solar Mass Black Hole
• AT 2018cow VLBI: No Long-Lived Relativistic Outflow
• A hot and luminous source at the site of the fast transient AT2018cow at 2-3 years after its explosion
• Possible ~0.4 hour X-ray quasi-periodicity from an ultrasoft active galactic nucleus
• HI 21cm mapping of the host galaxy of AT2018cow: a fast-evolving luminous transient within a ring of high column density gas
• ALMA Polarimetry of AT2018cow
• Detection of Millihertz Quasi-Periodic Oscillations in the X-Ray Binary 1RXS J180408.9$-$342058
• ALMA observations of molecular gas in the host galaxy of AT2018cow
• Phase-resolved spectral analysis of the 11 millihertz quasi-periodic oscillation in the black-hole candidate H1743-322

Cited by in corpus (8)

• Science objectives of the Einstein Probe mission
• Minutes-duration Optical Flares with Supernova Luminosities
• Late-time Hubble Space Telescope Observations of AT 2018cow. II. Evolution of a UV bright Underlying Source 2--4 Yr Post-discovery
• Multi-wavelength observations of the Luminous Fast Blue Optical Transient AT2023fhn
• An 85-s X-ray quasi-periodicity after a stellar tidal disruption by a candidate intermediate-mass black hole
• Luminous Fast Blue Optical Transients as "Failed" Gravitational-wave Sources: Helium Core$-$Black Hole Mergers Following Delayed Dynamical Instability
• The spectra of a radiative reprocessing outflow model for fast blue optical transients
• AT2019ijn: a fast-rising, slow-decaying blue optical transient with exceptionally bright radio emission