Authenticating the Presence of a Relativistic Massive Black Hole Binary in OJ 287 Using its General Relativity Centenary Flare: Improved Orbital Parameters

TL;DR

This paper refines the orbital model of the black hole binary in OJ 287 by including higher-order gravitational wave effects, achieving precise flare timing predictions that test fundamental black hole properties.

Contribution

It introduces an advanced model incorporating hereditary gravitational wave effects to accurately predict impact flare timings in OJ 287, enabling tests of the black hole no-hair theorem.

Findings

Excellent agreement between predicted and observed flare timings.

Orbital period decay rate is nine orders of magnitude higher than in PSR 1913+16.

Timing of the 2019 impact flare can test the black hole no-hair theorem.

Abstract

Results from regular monitoring of relativistic compact binaries like PSR 1913+16 are consistent with the dominant (quadrupole) order emission of gravitational waves (GWs). We show that observations associated with the binary black hole central engine of blazar OJ 287 demand the inclusion of gravitational radiation reaction effects beyond the quadrupolar order. It turns out that even the effects of certain hereditary contributions to GW emission are required to predict impact flare timings of OJ 287. We develop an approach that incorporates this effect into the binary black hole model for OJ~287. This allows us to demonstrate an excellent agreement between the observed impact flare timings and those predicted from ten orbital cycles of the binary black hole central engine model. The deduced rate of orbital period decay is nine orders of magnitude higher than the observed rate in PSR 1913+16, demonstrating again the relativistic nature of OJ 287's central engine. Finally, we argue that precise timing of the predicted 2019 impact flare should allow a test of the celebrated black hole "no-hair theorem" at the 10% level.