标题： 是什么决定了受活动星系核协助的黑洞合并的最大质量？ 显示英文标题

标题： What Determines the Maximum Mass of AGN-assisted Black Hole Mergers?

摘要： 通过引力波探测到的并合双黑洞的起源仍然是天体物理学中的一个基本问题。虽然恒星演化对黑洞设定了大约50倍太阳质量的上限，但一些观测到的并合事件——最显著的是GW190521——涉及明显更高质量的成分，这表明存在替代的形成通道。在这里，我们研究了在活动星系核（AGN）盘内并合的重黑洞可能成为什么。利用一个综合的半解析模型，该模型结合了27个二元和环境参数，我们探讨了AGN盘条件在塑造黑洞质量谱高端部分所起的作用。我们发现，AGN盘的寿命是主导因素，只有当盘持续约40百万年时，才会发生高质量并合（>200倍太阳质量）。因此，AGN辅助并合的联合电磁观测可以因此直接测量AGN盘的年龄。 显示英文摘要

摘要： The origin of merging binary black holes detected through gravitational waves remains a fundamental question in astrophysics. While stellar evolution imposes an upper mass limit of about 50 solar mass for black holes, some observed mergers--most notably GW190521--involve significantly more massive components, suggesting alternative formation channels. Here we investigate how heavy black holes merging within Active Galactic Nucleus (AGN) disks can become. Using a comprehensive semi-analytic model incorporating 27 binary and environmental parameters, we explore the role of AGN disk conditions in shaping the upper end of the black hole mass spectrum. We find that AGN disk lifetime is the dominant factor, with high-mass mergers (>200 solar mass) only possible if disks persist for ~40 Myr. The joint electromagnetic observation of an AGN-assisted merger could therefore lead to a direct measurement of the age of an AGN disk.