Related papers: The Unique Blazar OJ 287 and its Massive Binary Bl…

Binary black hole (BH) central engine description for the unique blazar OJ 287 predicted that the next secondary BH impact-induced bremsstrahlung flare should peak on 2019 July 31. This prediction was based on detailed general relativistic…

We try to propose a tentative relativistic jet model for explaining the entire radio-optical phenomena observed in blazar OJ287, which has been observed quasi-periodically with a cycle of about 12yr in its optical light curve. We…

Supermassive binary black holes (SBBHs) are a natural outcome of galaxy mergers. Here we show that low-frequency ($f \leq 10^{-6}$ Hz) quasi-periodic variability observed from cosmic blazar sources can provide substantial inductive support…

The light curve of the quasar OJ 287 extends from 1891 up today without major gaps. Here we summarize the results of the 2005 - 2010 observing campaign. The main results are the following: (1) The 2005 October optical outburst came at the…

Blazar OJ287 is a unique source in which optical outbursts with double-peak structure have been observed quasi-periodically with a cycle of 12yr. It may be one of the best candidates for searching supermassive black hole binaries. We…

We perform Bayesian targeted searches for continuous gravitational waves from eccentric supermassive binary black holes (SMBBHs) using the Parkes Pulsar Timing Array third data release (PPTA DR3). Six electromagnetically motivated sky…

Recent intensive observations of the BL Lac object OJ 287 raise a lot of questions on the models of binary black holes, processing jets, rotating helical jets and thermal instability of slim accretion disks. After carefully analyzing their…

The fascination with the blazar OJ 287 stems not only from its status as a prominent candidate for a close supermassive black hole (SMBH) binary, but also because of the thermal bremsstrahlung origin proposed for its giant optical…

Blazar OJ287 exhibits large thermal flares at least twice every 12 years. The times of these flares have been predicted successfully using the model of a quasi-Keplerian eccentric black hole binary where the secondary impacts the accretion…

Tests of Einstein's general theory of relativity have mostly been carried out in weak gravitational fields where the space-time curvature effects are first-order deviations from Newton's theory. Binary pulsars provide a means of probing the…

We report on a LUCI/Large Binocular Telescope near-infrared (NIR) spectrum of PSO J030947.49+271757.31 (hereafter PSO J0309+27), the highest redshift blazar known to date (z$\sim$6.1). From the C$\rm IV$$\lambda$1549 broad emission line we…

OJ 287 is a bright blazar with century-long observations, and one of the strongest candidates to host a supermassive black hole binary. Its polarisation behaviour between 2015 and 2017 (MJD 57300-58000) contains several interesting events…

The bright blazar OJ~287 routinely parades high brightness bremsstrahlung flares, which are explained as being a result of a secondary supermassive black hole (SMBH) impacting the accretion disc of a more massive primary SMBH in a binary…

We have studied short-term variations of the blazar OJ 287, suspected to host a supermassive black hole binary. In this study, we use a two-season optical R-band dataset from 2004--2006 which consists of 3991 data points from the OJ 287…

Our project MOMO (Multiwavelength observations and modelling of OJ 287) consists of dedicated, dense, long-term flux and spectroscopic monitoring and deep follow-up observations of the blazar OJ 287 at >13 frequencies from the radio to the…

The quasar J1918+4937 was recently suggested to harbour a milliparsec-separation binary supermassive black hole (SMBH), based upon modeling the narrow spike in its high-cadence Kepler optical light curve. Known binary SMBHs are extremely…

We present a summary of the results of the OJ 287 observational campaign, which was carried out during the 2021/2022 observational season. This season is special in the binary model because the major axis of the precessing binary happens to…

OJ 287, a nearby blazar, has exhibited remarkable variability in its optical light curve since 1888, characterized by ~12-year quasi-periodic outbursts. These events are attributed to the orbital dynamics of a supermassive binary black hole…

We report results from our ongoing project MOMO (Multiwavelength Observations and Modelling of OJ 287). In this latest publication of a sequence, we combine our Swift UVOT--XRT and Effelsberg radio data (2.6-44 GHz) between 2019 and 2022.04…

Recent astrophysical models predict that stellar-mass binary black holes (BBHs) could form and coalesce within a few gravitational radii of a supermassive black hole (SMBH). Detecting the gravitational waves (GWs) from such systems requires…