Active Galactic Nuclei

Almost all galaxies host in their center a supermassiveblack hole of mass between a million and tens of billions solar masses. Supermassive black holes grow in symbiosiswith their host galaxies across the Hubble time, occasionally accretingsurround matter, giving rise to an Active Galactic Nuclei (AGN). This book gives a general review of our current knowledgeof AGN, powered by supermassive black holes: how they are fueled by gas (orstars) and what problems are encountered; how can we account for the widevariety of AGN, from Seyfert/Liners to quasars, and for the two types (AGN 1and 2) either through dust obscuration, and geometrical orientation arguments,or through intrinsic activity difference, qualitative or quantitative. Withmodern instruments, providing high resolution and sensitivity, like ALMA inradio, or MUSE at the ESO/VLT, it is possible to unveil the interstellar mediumand stars in the circumnuclear regions, discover molecular disks and tori, inthe sphere of influence of the black holes. While AGN are accreting matter,they are providing so much energy that part of the surrounding gas is expelledand is observed in molecular outflows, identified as the main feedback processof AGN on their host.Key Features:Reviews ourcurrent knowledge of AGN, with case studies and examples of observed AGN intheir host galaxies.Discusses thelong-standing problem of AGN fueling and feedback, and proposes educatedmodels of the circum-nuclear regions, which are still difficult to resolve.Covers recentadvances in the field of AGN research provided by current astronomicalinstrumentation (e.g., ALMA, VLT).Written by aworld-leading expert in the field.