Is OJ 287 a Single Supermassive Black Hole?

Butuzova, M. S.; Pushkarev, A. B.

doi:10.3390/universe6110191

Cited by 25 publications

(28 citation statements)

References 51 publications

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“…Kushwaha, 2020). Such strong spectral changes are inconsistent with the simple jet-precession scenarios (Britzen et al, 2018;Butuzova & Pushkarev, 2020, and references therein) invoked for the QPOOs in which only achromatic flux boosting is expected without any spectral changes. If this interpretation is indeed the case, it requires strong dynamical mechanisms with very efficient radiative output -like that of accretion or jet to account for these spectral features with dynamical forces peaking around the expected QPOOs to drive the spectral changes.…”

Section: Accretion Physicsmentioning

confidence: 74%

The BL Lac Object OJ 287: Exploring a Complete Spectrum of Issues Concerning Relativistic Jets and Accretion

Kushwaha¹

2021

Preprint

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The BL Lacertae object OJ 287 is one of the most dynamic blazars across the directly accessible observational windows -spectral, timing, polarization, and imaging. In addition to behaviors considered characteristics of blazars, it exhibits peculiar timing features like quasi periodicity in optical flux, radio-detected knots position, and has shown diverse transient spectral features like a spectral phase dominated by a new broadband emission component, Seyfert-like soft-X-ray excess, iron line absorption, a thermal-like emission dominated optical phase, large polarization swings associated with one of the timing features, etc. that are rare in blazars and contrary to currently prevailing view of BL Lacs. Theoretical considerations, supported by existing observations, invoke scenarios involving a dynamical interplay of accretion and/or strong-gravity-induced events (tidal forces) in a binary supermassive black hole (SMBH) scenario to impact-induced jet and only jet activities. A few of these models even make some definite and quite distinctive observationally testable predictions. These considerations make OJ 287 the only blazar/jetted-AGN to have an activity phase with dominance related to accretion and/or accretion-perturbation-induced jet activities. We present a brief overview of the unique spectral features and discuss the implications of these features in exploring not only relativistic jet physics but issues from accretion to accretion-regulated jet activities i.e. the whole spectrum of issues related to the jet-accretion paradigm in jetted SMBH systems that have not been possible so far due to jet emission shadowing other likely emission features/components.

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Section: Accretion Physicsmentioning

confidence: 74%

The BL Lac Object OJ 287: Exploring a Complete Spectrum of Issues Concerning Relativistic Jets and Accretion

Kushwaha¹

2021

Preprint

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“…OJ 287 has been argued to host a sub-parsec binary SMBH on the basis of quasi periodic optical outbursts (QPOOs) every ∼ 12-yr (Sillanpaa et al 1988;Dey et al 2018, and references therein but see Britzen et al (2018); Butuzova & Pushkarev (2020)). The latest of these outbursts occurred in 2015-end (Valtonen et al 2016) and mid-2019 (Laine et al 2020).…”

Section: Discussionmentioning

confidence: 99%

“…Other prominent features are an apparent periodicity of a few years in the position of quasistationary radio knots seen at 15 GHz, as well as a ∼22 yr periodicity (Britzen et al 2018), and a claim of ∼30-yr period from another study (Cohen 2017). These inferences from radio bands are the basis of claim of a precessing and rotating jet in OJ 287, and models based on precession for the recurring ∼12-yr optical flares (Cohen 2017;Britzen et al 2018;Butuzova & Pushkarev 2020).…”

Section: Introductionmentioning

confidence: 99%

Spectral States of OJ 287 blazar from Multi-wavelength Observations with $AstroSat$

Singh,

Kushwaha,

Sinha

et al. 2021

Preprint

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We present AstroSat soft X-ray, near-UV (NUV) and far-UV (FUV) observations of a blazar, OJ 287, carried out in 2017, 2018, and 2020. The simultaneous observations with NuSTAR in 2017 provide a broad-band look encompassing NUV, FUV, soft and hard X-rays. Captured in three different broadband spectral states in three observations, the X-ray spectrum is found to be the hardest during 2018, while the high-energy-end of the simultaneous optical-FUV spectrum shows a steepening that is modeled with a broken power-law spectrum. The spectral energy distribution (SED) in 2017 shows a relatively flatter optical-FUV and soft X-ray spectra, implying an additional emission component. The 2020 optical-FUV spectrum is harder than in 2017 and 2018, with an extremely soft X-ray spectrum and a hardening above ∼1 GeV, similar to the SEDs of High-energy-peaked BL Lac objects (HBL), thereby establishing that this additional emission component has HBL-like properties. The AstroSat multi-wavelength observations trace the spectral evolution from the end-phase of the HBL component in 2017 to its disappearance in 2018 followed by its revival in 2020. A single zone leptonic model reproduces the 2018 broadband spectrum while the 2017 and 2020 SEDs require an additional HBL-like emitting zone. The spectral evolution of the high-energy-end of optical-UV spectrum, revealed by the FUV observations in 2017 and 2018, strongly suggests that X-ray spectral changes in the normal broadband spectral state of OJ 287 are primarily due to the evolution of the optical-UV synchrotron spectrum.

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“…Often for interpretation of the observed properties (e.g. Bach et al 2005;Rastorgueva et al 2011b;Rani et al 2015;Lister et al 2013Lister et al , 2016Butuzova 2018a,b;Butuzova & Pushkarev 2020), the jet is assumed to be curved, which implies different Doppler factors for its various parts. Since we consider the jet as a whole and it is more extended than the optical core, the possible variability of the total radiation flux of the jet caused by geometric effects occurs on longer time scales and with a smaller amplitude of the brightness change.…”

Section: Two Emission Regionsmentioning

confidence: 99%

Long-term multiband optical variability of S5 0716+714 blazar

Gorbachev,

Butuzova,

Sergeev

et al. 2022

Preprint

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Multiband optical photometry data of blazar S5 0716+714 obtained from 2002 to 2019 reveal stable color index change with flux variability. We analyzed this trend under variability caused by the Doppler factor change in the presence of a curved photon energy spectrum. A break in the energy spectrum of emitting electrons, caused by radiative losses, or log-parabolic electron energy distribution, or the synchrotron self-absorption acting in a compact jet part forms such the photon spectrum. We explained the observed color index change with variability by geometric effects only under the assumption that the radiating region is the synchrotron self-absorbed core and the bright optically thin jet. In this framework, we estimated the magnetic field strength in the optically thick part of the radiating region. These values correspond to other independent estimates of the magnetic field near the black hole, further supporting our assumption.

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Is OJ 287 a Single Supermassive Black Hole?

Cited by 25 publications

References 51 publications

The BL Lac Object OJ 287: Exploring a Complete Spectrum of Issues Concerning Relativistic Jets and Accretion

The BL Lac Object OJ 287: Exploring a Complete Spectrum of Issues Concerning Relativistic Jets and Accretion

Spectral States of OJ 287 blazar from Multi-wavelength Observations with $AstroSat$

Long-term multiband optical variability of S5 0716+714 blazar

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