The Ins and Outs of Black Hole Accretion

在大多数星系的中心都存在着一个比太阳大几百万甚至几十亿倍的超大质量黑洞。 其中一些怪物非常活跃，它们可以使周围的物质比其宿主星系中的所有恒星都亮。 最接近黑洞的物质，就在它即将跳出事件视界的时候，是如此的热，以至于辐射出X射线，它受到宇宙中最猛烈的条件。 黑洞的极端引力可以将恒星撕裂，并以接近光速的速度将物质抛向周围，然后最终被吞噬。 有时这种物质会被猛烈地抛出，以至于它完全从黑洞区域被抛出，并被抛回星系附近，在那里它可能对宿主星系的条件产生巨大的影响。 用太空X射线天文台观测这些活跃的星系可能是研究黑洞环境中奇异物理学的唯一途径。 环境是什么样子的？物质是如何落入黑洞的，它是由什么组成的？黑洞附近的物质是如何从系统中喷射出来的？ 这些喷出物如何影响黑洞所在的宿主星系？这些只是我的团队在这项工作中将要解决的几个问题，试图了解黑洞如何生长和星系如何演化。 2021年，XRISM X射线天文台将启动，它将拥有X射线天文学中最高能量分辨率的仪器。 这意味着我们可以准确地确定黑洞周围物质的成分和温度，以及它移动的方向和速度。 我们将能够准确地区分落入或逃离黑洞的物质。 我们将能够确定黑洞周围物质的几何学和运动学。 我们的加拿大学生将回答这个研究计划提出的基本问题。 通过与大自然中最奇特的生物进行对抗，我们正在建设加拿大天基研究的能力和知识。

A supermassive black hole that is millions or even billions of times more massive than the Sun resides at the centres of most galaxies. Some of these monsters are so active that they can make the surrounding material shine brighter than all the stars in its host galaxy. The material closest to the black hole, just as it is about to plunge beyond the event horizon, is so hot it radiates X-rays and it is subjected to the most violent conditions in the Universe. The extreme gravity of the black hole can tear stars apart and fling matter around at velocities close to the speed of light before it is finally ingested. Sometimes this material can be thrown out so violently that it is completely ejected from the black hole region and hurled back into the galactic neighbourhood where it may have a resounding effect on the conditions in the host galaxy. Observing these active galaxies with space-based X-ray observatories may be the only way to study the exotic physics at work in the black hole environment. What does the environment look like? How is material falling into the black hole and what is it made of? How does material near a black hole get ejected from the system? How does this ejecta influence the host galaxy that the black hole resides in? These are only a few questions that my team will be tackling over the course of this work to try understanding how black holes grow and galaxies evolve. In 2021, the XRISM X-ray observatory will be launched and it will have the highest energy resolution instruments every available in X-ray astronomy. This means we can accurately determine the composition and temperature of the material around black holes, and the direction and speed at which it is moving. We will be able to accurately distinguish material that is falling into or escaping from the black hole. We will be able to determine the geometry and kinematics of the material around black holes. Our Canadian students will be the ones answering the fundamental questions posed by this research program. By confronting Nature's most exotic creatures, we are building capacity and knowledge in space-based research in Canada.