A supermassive binary black hole in the quasar 3C 345
A supermassive binary black hole in the quasar 3C 345
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DOI：
10.1051/0004-6361:20041831
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发表时间：
2004-11
影响因子：
6.5
通讯作者：
A. Lobanov;J. Roland
中科院分区：
文献类型：
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作者：
A. Lobanov;J. Roland
射电大声的活动星系核呈现出各种各样的迹象，表明存在可能起源于超大质量黑洞双星系统的周期性过程，其中轨道运动和岁差是观测到的宽带发射变化以及秒差距尺度上射电发射的形态学和运动学特性的最终原因。这种情况下，适用于类星体3C 345，解释了观测到的无线电和光学发射的变化，从类星体，并再现了结构变化中观察到的这个对象的秒差距尺度喷流。3C 345双星系统是由两个质量相等的黑洞组成的，它们的质量为107.1 × 108 M，距离为103.33pc，轨道周期为10480 yr。轨道运动引起吸积盘围绕主黑洞的进动，周期为2570年。射流等离子体描述为一个磁化的，相对论性的电子-正电子束内传播更广泛和更慢的电子-质子射流。光束的阿尔芬波扰动、双星系统的轨道运动和吸积盘的进动的组合再现了3C 345中光通量的变化和射电结构的演化。3C 345的准周期耀斑活动的时间尺度与典型的盘不稳定性时间尺度一致。目前的模型不能排除一个小质量的轨道飞行器穿过吸积盘并引起准周期耀斑的可能性。
Radio loud active galactic nuclei present a remarkable variety of signs indicating the presence of periodical processes possibly originating in binary systems of supermassive black holes, in which orbital motion and precession are ultimately responsible for the observed broad-band emission variations, as well as for the morphological and kinematic properties of the radio emission on parsec scales. This scenario, applied to the quasar 3C 345, explains the observed variations of radio and optical emission from the quasar, and reproduces the structural variations observed in the parsec-scale jet of this object. The binary system in 3C 345 is described by two equal-mass black holes with masses of ≈7.1 × 10 8 Mseparated by ≈0.33 pc and orbiting with a period ∼480 yr. The orbital motion induces a precession of the accretion disk around the primary black hole, with a period of ≈2570 yr. The jet plasma is described by a magnetized, relativistic electron-positron beam propagating inside a wider and slower electron-proton jet. The combination of Alfven wave perturbations of the beam, the orbital motion of the binary system and the precession of the accretion disk reproduces the variability of the optical flux and evolution of the radio structure in 3C 345. The timescale of quasi-periodic flaring activity in 3C 345 is consistent with typical disk instability timescales. The present model cannot rule out a small-mass orbiter crossing the accretion disk and causing quasi-periodic flares.