Signals from the edge of the abyss: quasi-periodic oscillations in active galactic nuclei

当物质螺旋进入黑洞时，它会升温并释放出x射线。来自这个吸积盘的x射线编码了物质在高度弯曲时空区域的行为信息。辐射的可变性是由于一些噪声过程，除了偶尔有准周期振荡（QPOs）。这些qpo的快速时间尺度表明，它们一定与非常接近黑洞本身的动态或辐射事件有关。虽然早在x射线双星的盘面上就发现了含有恒星质量黑洞的QPOs，但直到最近10年左右，才有证据表明QPOs也存在于活动星系核（AGN）中，其中含有超大质量黑洞（SMBHs）。最近的研究表明，QPOs在AGN中的存在实际上可能比以前认为的要广泛得多。该项目的目标是建立定位AGN中QPOs的新方法，并利用这些方法来了解创建它们的过程。这将需要编码、数据分析和使用x射线观测技术。

As matter spirals onto a black hole, it heats up and emits X-rays. The X-rays from this accretion disc encode information about how matter behaves in the region of highly curved space-time. The variability of the radiation is due to a number of noise processes, in addition to which there are - occasionally - Quasi-periodic oscillations (QPOs). The rapid timescales of these QPOs indicate they must be associated with something dynamic or radiative occurring very close to the black hole itself. Whilst QPOs have long been observed from the discs of X-ray binaries harbouring stellar mass black holes, it is only in the last 10 years or so that evidence has emerged that QPOs are also present in active galactic nuclei (AGN), harbouring supermassive black holes (SMBHs). Recent studies have indicated that the presence of QPOs may in fact be much more widespread in AGN that previously thought.The aims of the project will be to build new methods of locating QPOs in AGN and exploit these to understand the processes creating them. This will entail coding, data analysis and the use of X-ray observational techniques.