Authors:
Komossa, S.;Grupe, D.;Kraus, A.;Gonzalez, A.;Gallo, L. C.;Valtonen, M. J.;Laine, S.;Krichbaum, T. P.;Gurwell, M. A.;Gómez, J. L.;Ciprini, S.;Myserlis, I.;Bach, U.
Journal:
Monthly Notices of the Royal Astronomical Society
Abstract:
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 with public SMA data and gamma-ray data from the Fermi satellite. The observational epoch covers OJ 287 in a high state of activity from radio to X-rays. The epoch also covers two major events predicted by the binary supermassive black hole (SMBH) model of OJ 287. Spectral and timing analyses clearly establish: a new UV-optical minimum state in 2021 December at an epoch where the secondary SMBH is predicted to cross the disc surrounding the primary SMBH; an overall low level of gamma-ray activity in comparison to pre-2017 epochs; the presence of a remarkable, long-lasting UV-optical flare event of intermediate amplitude in 2020-2021; a high level of activity in the radio band with multiple flares; and particularly a bright, ongoing radio flare peaking in 2021 November that may be associated with a gamma-ray flare, the strongest in 6 yr. Several explanations for the UV-optical minimum state are explored, including the possibility that a secondary SMBH launches a temporary jet, but the observations are best explained by variability associated with the main jet.
URL:
https://ui.adsabs.harvard.edu/#abs/2022MNRAS.513.3165K/abstract
Keywords:
galaxies: active;galaxies: jets;galaxies: nuclei;quasars: individual (OJ 287);(galaxies:) quasars: supermassive black holes;X-rays: galaxies;Astrophysics - High Energy Astrophysical Phenomena;Astrophysics - Astrophysics of Galaxies