雙超大質量黑洞系統隨著宇宙演化的表徵為瞭解星系/超大質量黑洞組成的關鍵，並可藉其預測雙黑洞系統產生之低頻率重力波訊號。在兩個星系進行合併之後，由於恆星之間產生之動態摩擦抑或其他動態過程，分別存在星系中的超大質量黑洞將逐漸演化為一個相距僅數個秒差距的雙黑洞系統。研究雙超大質量黑洞系統的演化，例如從兩個黑洞相距數萬光年開始至大約十幾個秒差距的過程，能讓我們了解活躍星系核在雙超大質量黑洞系統中的工作原理及其動態演化。在這場演講中，我將回顧目前對於雙超大質量黑洞系統在星系合併中演化的研究，並總結目前觀測上如何發現在宇宙正午時期(紅位移約為2左右)誕生的星系級雙超大質量黑洞系統。我將特別著重在多波段觀測對於了解這類天體不論是統計上以及其物理性質的重要性。
Characterization of the binary supermassive black hole (SMBH) population over cosmic history is a critical pathway to understanding galaxy/SMBH assembly and forecasting low-frequency gravitational wave detection in the coming decades. Following the merger of two galaxies, the two SMBHs within each of the galaxies will eventually evolve into a bound binary, separated by a few parsec, via dynamical friction with stars and other dynamical processes. Studying SMBH pairs at different evolutionary stages, e.g., from tens of kpc separations at the beginning of the merger to ~10 parsec scales of bound binaries, provides the foundation to understanding AGN fueling in mergers and the dynamical evolution of SMBH pairs. In this talk, I will review our current understanding of how SMBH pairs evolve in galaxy mergers, and summarize observational efforts of identifying the population of galactic-scale SMBH pairs at cosmic noon (z~2). In particular, I will highlight the importance of multi-wavelength observations on constraining the statistics of these objects as well as detailed studies of their physical properties.
