1. MOMO – V. Effelsberg, Swift, and Fermi study of the blazar and supermassive binary black hole candidate OJ 287 in a period of high activity.
- Author
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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, and Bach, U
- Subjects
BL Lacertae objects ,SUPERMASSIVE black holes ,BINARY black holes ,SOLAR flares ,CORONAL mass ejections ,ACTIVE galaxies - 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. [ABSTRACT FROM AUTHOR]
- Published
- 2022
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