Outflows from Accreting Black Holes in Active Galactic Nuclei

强大的风和喷流是活跃星系核（AGN）中吸积黑洞最引人注目的表现之一。最近对吸积流能量学的研究表明，这种流出不仅是不可避免的，而且质量损失可能如此之大，以至于除了一小部分供应物质外，所有物质在到达黑洞之前都被排出。该项目研究了AGN吸积新观点的理论分支和观测结果。虽然质量、角动量和能量的损失以一种可预测的方式相互关联，但流出的具体情况取决于微物理细节。Begelman博士正在构建“流入-流出”模型，计算它们的辐射特性，并研究它们与相对论性射流的产生和准直的关系，以及它们与AGN环境的相互作用。agn中的相对论性喷流可能是吸积流内部大量质量损失的结果之一，但喷流也可能从黑洞的旋转中获得大部分能量。Begelman博士也在研究通过Blandford-Znajek效应提取自旋能如何取决于黑洞的吸积历史和当前环境。Begelman博士也在研究宽z射线铁线和相对论的“盘震学”——研究吸积盘内部区域的被困振荡——作为靠近黑洞的强引力区域的观测探测器。* * *

Powerful winds and jets are among the most dramatic manifestations of accreting black holes in active galactic nuclei (AGN). Recent consideration of the energetics of accretion flows suggests that such outflows are not only inevitable, but that the mass loss may be so strong that all but a tiny fraction of the supplied matter is expelled before it reaches the black hole. This project studies the theoretical ramifications and observational consequences of this new view of accretion in AGN. Although the loss of mass, angular momentum, and energy are interrelated in a predictable way, the specifics of the outflows depend on microphysical details. Dr. Begelman is constructing "inflow-outflow" models, calculating their radiative properties, and studying their relationships to the production and collimation of relativistic jets as well as their interactions with the AGN environment.The relativistic jets in AGNs may be one consequence of powerful mass loss from the inner parts of accretion flows, but the jets could also derive much of their energy from the spin of the black hole. Dr. Begelman is also studying how the extraction of spin energy via the Blandford-Znajek effect depends on the black hole's accretion history and its current environment. Dr. Begelman is also studying the braod z-ray iron lines and relativistic "diskoseismology" - the study of trapped oscillations in the inner regions of accretions disks - as observational probes of strong gravity regions close to black holes. ***