Absence of the predicted 2022 October outburst of OJ 287 and implications for binary SMBH scenarios

The project MOMO (Multiwavelength Observations and Modelling of OJ287) was set up to test predictions of binary supermassive black hole (SMBH) scenarios and to understand disc-jet physics of the blazar OJ287. After a correction, the precessing binary (PB) SMBH model predicted the next main outburst of OJ287 in 2022 October, making the outburst well observable and the model testable. We have densely covered this period in our ongoing multifrequency radio, optical, ultraviolet (UV), and X-ray monitoring. The predicted outburst was not detected. Instead, OJ287 was at low optical-UV emission levels, declining further into November. The predicted thermal bremsstrahlung spectrum was not observed either, at any epoch. Further, applying scaling relations, we estimate an SMBH mass of OJ287 of 10(8) M-circle dot. The latest in a sequence of deep low states that recur every 1-2 yr is used to determine an upper limit on the Eddington ratio and on the accretion-disc luminosity. This limit is at least a factor of 10 lower than required by the PB model with its massive primary SMBH of >10(10) M-circle dot. All these results favour alternative binary SMBH models of OJ287 that require neither strong orbital precession nor a very large mass of the primary SMBH.

Automated summary

The MOMO project aimed to test predictions of binary supermassive black hole scenarios and understand the disc-jet physics of OJ287. After correction, the precessing binary SMBH model predicted an observable outburst in October 2022, but it was not detected. The results favor alternative binary SMBH models that do not require strong orbital precession or a very large mass.