利用VLBI观测和研究超大质量双黑洞

超大质量双黑洞的形成是星系的并合演化理论的必然结果，其吸积和反馈是黑洞-星系协同演化的重要原因，与中央黑洞活跃性和质量的增长密切相关，处于亚秒差距尺度的超大质量双黑洞在绕转和并合过程中产生的低频引力波辐射是未来空间干涉引力波天文台和脉冲星计时阵列的重要观测目标。超大质量双黑洞的存在与否、丰度、并合率等关系到超大质量双黑洞的演化理论、低频引力波辐射源和低频引力波背景的强度。因此，对其进行搜寻和观测研究意义重大，然而目前证认的超大质量双黑洞数目很少，与理论预言严重不符，对星系的并合演化理论和超大质量双黑洞的演化模型提出了重大的挑战。本项目拟利用以甚长基线干涉为主的方法在周期性光变类星体、具有光学多核的星系、扭曲形态喷流的射电星系等中搜寻和证认超大质量双黑洞。

It was expected that supermassive binary black holes (SMBBH) will be formed in the course of a merger event according to the hierarchical galaxy formation model. The accretion and feedback of SMBBH is the key to the BH-host coevolution and activity and growth of BH, furthermore, sub-pc scale SMBBH and the coalesce can produce a strong low-frequency gravitational-wave, which can be detected by the future gravitational wave detector such as LISA and PTA. The existence, abundance and coalesce rate of SMBBH can not only provide the observation evidence of SMBBH evolution theory but the target of low-frequency gravitational-wave and strength of gravitational-wave background. It is important to search and study SMBBH, however, the identified SMBBH is very rare and inconsistent with the prediction, which is challenging the theory. Here in this project, we would like to use the very long baseline interferometry to search and study the supermassive binary black hole candidates, including periodic variable quasars, optical dual-core galaxies, bending-jet radio galaxies and so on.