标题： 超大质量黑洞及其周围环境：兆电子伏特特征 显示英文标题

标题： Supermassive black holes and their surroundings: MeV signatures

摘要： 超大质量黑洞的引力势如此强大，以至于它会引发宇宙中最强烈的现象之一。 这些天体的吸积过程以及其附近产生的相对论性喷流，在广泛的频率范围内以及整个宇宙历史上都可以被观测到。 然而，尽管有大量数据，它们的基本机制的许多方面仍然难以捉摸。 在所有频率范围内研究这种现象至关重要，但某些能量窗口仍未得到充分探索。 其中一个窗口是兆电子伏特（MeV）能量范围：许多与超大质量黑洞环境发射相关的关键特征——无论是平静还是活跃阶段——预计位于一到几百兆电子伏特之间。 在本工作中，我们探讨了一些关于超大质量黑洞周围行为和发射过程的开放性问题，以及这些问题可能的解决方法。 从我们银河系中心周围费米气泡的难以捉摸的性质，到活动星系核核区和喷流中高能中微子的起源，再到最强大的耀变体的性质和发射机制，兆电子伏特窗口被突出为理解超大质量黑洞物理的关键钥匙。 显示英文摘要

摘要： The gravitational potential of supermassive black holes is so powerful that it triggers some of the most intense phenomena in the Universe. Accretion onto these objects and relativistic jet emission from their vicinity are observable across a wide range of frequencies and throughout cosmic history. However, despite this wealth of data, many aspects of their underlying mechanisms remain elusive. Investigating this phenomena across all frequencies is crucial, yet some energy windows are still poorly explored. One such window is the MeV energy range: many key signatures related to the emission from the SMBH environment - both in quiescent and active phases - are expected to lie between one and several hundreds MeV. In this work, we explore some of the open questions regarding the behavior and emission processes in the surroundings of SMBHs, and how these questions might be approached. From the elusive nature of Fermi bubbles around our Galactic Centre, to the origin of high-energy neutrinos in the nuclei and jets of Active Galactic Nuclei, to the nature and emission mechanisms of the most powerful blazars, the MeV window stands out as a crucial key to understanding SMBH physics.