Explaining temporal variations in the jet PA of the blazar OJ 287 using its BBH central engine model
Explaining temporal variations in the jet PA of the blazar OJ 287 using its BBH central engine model
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DOI：
10.1093/mnras/stab730
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发表时间：
2021-03
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影响因子：
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通讯作者：
L. Dey;M. Valtonen;A. Gopakumar;R. Lico;J. Gómez;A. Susobhanan;S. Komossa;P. Pihajoki
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文献类型：
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作者：
L. Dey;M. Valtonen;A. Gopakumar;R. Lico;J. Gómez;A. Susobhanan;S. Komossa;P. Pihajoki
明亮的耀变体OJ 287是最著名的超大质量黑洞双星系统的候选者。它是由于发射纳赫兹引力波（GW）而产生的。在其长达一个世纪的光学光变曲线中，对历史和预测的准周期高亮度耀斑的观测，使我们能够确定与双黑洞（BBH）中心引擎相关的轨道参数。相比之下，OJ 287的射电喷流仅在大约30年的时间里被甚长基线干涉测量（VLBI）观测所覆盖，这些观测表明喷流的位置角（PA）在毫米和厘米波长上都表现出时间变化。在这里，我们将观测到的OJ 287的PA变化与其射电喷流的进动联系起来。在我们的模型中，喷流方向的演化可以与主黑洞（BH）的自旋演化或与吸积盘的内部区域的角动量方向的进动。我们的贝叶斯分析表明，BBH中心引擎模型，主要是从光学观测，也可以广泛地解释所观察到的时间变化的无线电喷流的OJ 287在86，43和15 GHz的频率。OJ 287的全球毫米VLBI阵列（GMVA）观测有可能验证我们对其86 GHz PA值演变的预测。此外，由于事件视界望远镜（EHT）可以提供极高的角分辨率，我们探索了通过检测次级黑洞中的喷流来测试BBH模型的可能性。
The bright blazar OJ 287 is the best-known candidate for hosting a supermassive black hole binary system. It inspirals due to the emission of nanohertz gravitational waves (GWs). Observations of historical and predicted quasi-periodic high-brightness flares in its centurylong optical lightcurve, allow us to determine the orbital parameters associated with the binary black hole (BBH) central engine. In contrast, the radio jet of OJ 287 has been covered with Very Long Baseline Interferometry (VLBI) observations for only about 30 years and these observations reveal that the position angle (PA) of the jet exhibits temporal variations at both millimetre and centimetre wavelengths. Here we associate the observed PA variations in OJ 287 with the precession of its radio jet. In our model, the evolution of the jet direction can be associated either with the primary black hole (BH) spin evolution or with the precession of the angular momentum direction of the inner region of the accretion disc. Our Bayesian analysis shows that the BBH central engine model, primarily developed from optical observations, can also broadly explain the observed temporal variations in the radio jet of OJ 287 at frequencies of 86, 43, and 15GHz. OngoingGlobal mm-VLBIArray (GMVA) observations of OJ 287 have the potential to verify our predictions for the evolution of its 86 GHz PA values. Additionally, thanks to the extremely high angular resolution that the Event Horizon Telescope (EHT) can provide, we explore the possibility to test our BBH model through the detection of the jet in the secondary black hole .