Active Galactic Nuclei

Volker Beckmann received his Ph.D. from the University of Hamburg, Germany, for studies of different classes of Active Galactic Nuclei (AGN). He has been working in the field of hard X-ray astronomy in Italy, Switzerland, and in the US at NASA and taught at the University of Maryland, Baltimore County. As an expert on AGN, he has also worked on hard X-ray missions like INTEGRAL and Swift. Since 2009 he has been scientifically responsible for a new data and computing centre for astrophysics at the APC laboratory in Paris.Chris R. Shrader is an astrophysicist at the NASA Goddard Space Flight Center in Greenbelt Maryland and is also affiliated with the Universities Space Research Association. He has been involved with optical, ultraviolet, X-ray and gamma-ray studies of Active Galactic Nuclei as well as accretion-powered Galactic objects for over 25 years. He currently manages the Fermi Gamma-Ray Space Telescope Science Support Center.

• Preface IXAbbreviations and Acronyms XIAstronomical and Physical Constants XVColor Plates XVII1 The Observational Picture of AGN 11.1 From Welteninseln to AGN 11.2 Broad Lines, Narrow Lines, and the Big Blue Bump 31.3 Jets and Other Outflows 41.4 X-ray Observations: Probing the Innermost Regions 51.5 Up, Up and Away: from Gamma-Rays toward the TeV Range 72 Radiative Processes 112.1 Scattering of Photons 112.1.1 Thomson Scattering 112.1.2 Compton Scattering 122.1.3 Inverse Compton Scattering 152.1.4 Thermal Bremsstrahlung 172.1.5 Pair Production 202.2 Synchrotron Emission 212.2.1 Synchrotron Emission of a Particle Plasma 252.2.2 Polarization 272.2.3 Faraday Rotation 282.2.4 Synchrotron Self-Absorption 292.2.5 Synchrotron Self-Compton 323 The Central Engine 353.1 The Black Hole 353.1.1 Approaching a Black Hole 363.1.2 Evidence for Black Holes in AGN 373.1.3 Gravitational Field Near a Black Hole: the Schwarzschild Metric 423.1.4 Rotating Black Holes: the Kerr Metric 433.2 Accretion Processes 443.2.1 Accretion Basics: Bondi Accretion and the Eddington Limit 463.2.2 Accretion and Viscous Dissipation in a Thin Disk 483.2.3 Accretion in Thick Disks 513.2.4 Advection-Dominated Accretion Flows 523.3 Absorption Close to the Black Hole 543.3.1 The Torus Model 573.3.2 Mass Loss in AGN 593.4 Photoionization Modeling 633.5 Narrow and Broad-Line Regions 653.6 Reverberation Mapping: Probing the Scale of the BLR 733.7 AGN Jets: Emission, Dynamics and Morphologies 773.7.1 Raising the Jet 803.7.2 Shocks and Knots 843.7.3 Superluminal Motion 854 AGN Types and Unification 894.1 Seyfert Galaxies 894.1.1 Optical Classification 904.1.2 HII Regions 934.1.3 X-ray Classification 954.1.4 Narrow-Line Seyfert 1 Galaxies 964.2 Low-Luminosity AGN 994.3 Ultraluminous X-ray Sources 1014.4 Ultraluminous Infrared Galaxies – ULIRGs 1054.5 Radio Galaxies 1064.6 Quasars 1114.6.1 Radio-Quiet Quasars 1134.6.2 Radio-Loud Quasars 1154.7 Blazars 1164.8 Unification of AGN 1204.8.1 Absorbed versus Unabsorbed AGN 1224.8.2 Radio-Loud versus Radio-Quiet 1284.8.3 Breaking the Unification 1324.8.4 Grand Unification of Black Holes in the Universe 1365 AGN through the Electromagnetic Spectrum 1415.1 Radio: Probing the Central Engine 1415.2 Infrared: Dust Near and Far 1455.3 Optical: Where It All Began 1505.4 UV: The Obscured Inner Disk 1565.5 X-rays: Absorption, Reflection, and Relativistically Altered Line Profiles 1625.5.1 AGN in the X-ray from 1965 to the 1990s 1625.5.2 Today and Future X-ray Missions 1665.5.3 The X-ray Spectrum of AGN 1695.6 Gamma Rays: the Blazar-Dominated Sky 1775.7 VHE: the Evolving Domain 1825.7.1 The High-Energy End of the Spectrum 1885.8 The Whole Picture: the Spectral Energy Distribution 1885.8.1 SED of Blazars: a Whole Different Story 1915.8.1.1 The One-Zone Model 1935.8.1.2 External Compton Scattering 1975.8.2 The Spectral Energy Distribution of Nonbeamed Sources 2005.8.2.1 The Synchrotron Branch 2015.8.2.2 Dust in the SED 2025.8.2.3 The Disk Component 2035.8.2.4 The Inverse Compton Branch 2056 AGN Variability 2096.1 Variability in Radio-Quiet AGN 2096.2 Analysis Methods for Variability Studies 2126.3 Variability of Radio-Loud AGN 2206.4 Quasiperiodic Oscillations in AGN 2256.5 Rapid Variability 2287 Environment 2317.1 Host Galaxies of AGN 2317.1.1 Are There Naked Black Holes? 2327.1.2 Morphological Classification of Galaxies 2327.1.3 Host Galaxy and Black Hole Mass 2377.1.4 AGN-Host Galaxy Feedback 2407.2 The AGN–Starburst Connection 2427.2.1 Estimating the Star-Formation Rate 2437.2.2 AGN–Starburst Feedback 2447.3 Merging 2477.4 AGN in Clusters of Galaxies 2528 Quasars and Cosmology 2598.1 The Universe We Live in 2598.1.1 Geometry and Distances 2608.1.2 Measuring Fluxes 2658.1.3 The Three-Component Universe 2678.1.4 From the Big Bang to the Cosmic Microwave Background 2698.1.5 The Dark Matter Universe 2718.2 AGN and the Distribution of Matter on Large Scales 2729 Formation, Evolution and the Ultimate Fate of AGN 2819.1 The First AGN: How Did They Form? 2819.2 Tools to Study AGN Evolution 2869.2.1 The Number-Flux Relation 2869.2.2 The V/Vmax Test 2889.2.3 Luminosity Function 2909.3 Luminosity Functions of AGN 2949.4 AGN and the Cosmic X-ray Background 3009.5 The Late Stages of an AGN’s Life and Reignition SMBH 30410 What We Don’t Know (Yet) 30710.1 The Central Engine 30710.2 Environment, Interaction, and Feedback 31110.3 Origin, Evolution, and Fate 31210.4 Continuing the Quest 313References 315Index 347