Exploration of the origin of 2020 X-ray outburst in OJ 287

Abstract

Research into OJ 287 has been ongoing for many years. In 2020 April-June, this source underwent the second highest X-ray outburst (second only to the 2016-2017 outburst) and the mechanism of this outburst is still under debate. In this paper, we discuss two scenarios to explore the origin of the outburst: an after-effect of a black hole-disc impact and a tidal disruption event (TDE). We present the weak correlations of the spectral index versus X-ray flux and the hardness ratio (HR) versus the soft X-ray flux during the outburst, and these features are different from the case in the quiescent state. The correlations are compared with those of the 2016-2017 outburst with the highest X-ray flux in monitoring history. Analysis of the outbursts in 2016-2017 and 2020 shows that the expected time of the X-ray outburst, based on the theory of the after-effect of the black hole-disc impact and the estimation of available data, is inconsistent with historical observations. The soft X-ray spectra, the barely temporal evolution of colour, and the evolution of the HR mean that the 2020 outburst shares similar features with the 2016-2017 outburst, which was considered as a possible candidate for a TDE. Additionally, we find that the predictions of full TDEs ($t^{-5/3}$) and partial TDEs ($t^{-9/4}$) for the soft X-ray decay light curve are well fitted. Our analysis suggests that the 2020 outburst in OJ 287 is probably related to the TDE candidate.

13 pages, 11 figures and 3 tables, accepted by MNRAS

References in corpus (24)

• Tidal Disruption Events
• A massive binary black-hole system in OJ287 and a test of general relativity
• A tidal disruption event coincident with a high-energy neutrino
• The Superluminous Transient ASASSN-15lh as a Tidal Disruption Event from a Kerr Black Hole
• X-ray Quasi-Periodic Eruptions from two previously quiescent galaxies
• X-ray quasi-periodic eruptions from the galactic nucleus of RX J1301.9+2747
• The destruction and recreation of the X-ray corona in a changing-look Active Galactic Nucleus
• ASASSN-14ko is a Periodic Nuclear Transient in ESO 253-G003
• Delayed Radio Flares from a Tidal Disruption Event
• Tidal disruption events from supermassive black hole binaries
• Quasi-periodic Eruptions from Helium Envelope of Hydrogen-deficient Stars Stripped by Supermassive Black Holes
• Spitzer Observations of the Predicted Eddington Flare from Blazar OJ 287
• AT 2019avd: A novel addition to the diverse population of nuclear transients
• X-ray spectral components of the blazar and binary black hole candidate OJ 287 (2005-2020)
• A Tidal Disruption Event Candidate Discovered in the Active Galactic Nucleus SDSS J022700.77-042020.6
• AT2019 avd: A tidal disruption event with a two-phase evolution
• Light Curves of Partial Tidal Disruption Events
• Extreme variability in an active galactic nucleus: Gaia16aax
• MOMO IV: The complete Swift X-ray and UV/optical light curve and characteristic variability of the blazar OJ 287 during the last two decades
• Multi-wavelength Analysis and Modeling of OJ 287 During 2017-2020
• A possible tidal disruption event candidate in the black hole binary system of OJ 287
• Spectral States of OJ 287 blazar from Multi-wavelength Observations with $AstroSat$
• The GALEX Time Domain Survey. II. Wavelength-Dependent Variability of Active Galactic Nuclei in the Pan-STARRS1 Medium Deep Survey
• A comprehensive study of 2019-2020 flare of OJ 287 using AstroSat, Swift, and NuSTAR

Cited by in corpus (1)

• AT2018dyk Revisited: a Tidal Disruption Event Candidate with Prominent Infrared Echo and Delayed X-ray Emission in a LINER Galaxy