The Ins and Outs of Black Hole Accretion

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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.