Black Hole Accretion in Low-Luminosity Active Galactic Nuclei

AST 0206006 Quataert黑洞是爱因斯坦广义相对论的一个预言，代表着引力对宇宙中所有其他力的最终胜利;如此多的质量集中在如此小的体积中，以至于任何东西，甚至光，都无法逃脱。 在过去的十年里，天文学家提供了令人信服的证据，证明宇宙中大多数星系的中心都有一个巨大的黑洞;这些黑洞的质量比我们的太阳大100万到10亿倍。 这样的黑洞可以通过几种技术来探测，包括落入黑洞的热气体产生的辐射。 在某些情况下，这种气体产生的光比黑洞所在的宿主星系中数十亿颗恒星产生的光还要多。然而，大多数时候，大质量黑洞从吸积气体中产生的辐射少得令人惊讶。这项研究旨在了解能源生产的这一令人印象深刻的范围。Quataert博士及其合作者将对黑洞附近的热气体的性质进行理论计算，包括分析（“铅笔和纸”）和使用计算机模拟。 他们将专注于确定有多少气体福尔斯落入黑洞，以及这种气体产生多少辐射。 然后，他们将这些结果与甚大阵列（VLA）射电望远镜和钱德拉X射线天文台等设施的观测结果进行比较。

AST 0206006QuataertBlack holes, a prediction of Einstein's Theory of General Relativity, represent the ultimate victory of gravity over all other forces in the Universe; so much mass is concentrated in such a small volume that nothing, not even light, can escape. In the past decade, astronomers have provided convincing evidence that most galaxies in the Universe have a massive black hole at their center; these are a million to a billion times more massive than our Sun. Such black holes can be detected by several techniques, including the radiation produced by hot gas falling into the black hole. In some cases this gas produces more light than all of the billions of stars in the host galaxy which harbors the black hole. Most of the time, however, massive black holes produce surprisingly little radiation from accreting gas. This research is aimed at understanding this impressive range in energy production. Dr. Quataert and collaborators will carry out theoretical calculations of the properties of hot gas in the vicinity of a black hole, both analytically ("pencil and paper") and using computer simulations. They will focus on determining how much gas falls into a black hole and how much radiation this gas produces. They will then compare these results to observations from facilities such as the Very Large Array (VLA) Radio Telescope and the Chandra X-ray Observatory.***