Download or read book Radio Loudness of Active Galactic Nuclei written by and published by . This book was released on 2007 with total page 29 pages. Available in PDF, EPUB and Kindle. Book excerpt: We investigate how the total radio luminosity of AGN-powered radio sources depends on their accretion luminosity and the central black hole mass. Our studies cover about seven orders of magnitude in accretion luminosity (expressed in Eddington units, i.e. as Eddington ratios) and the full range of AGN black hole masses. We find that AGNs form two distinct and well separated sequences on the radio-loudness--Eddington-ratio plane. The ''upper'' sequence is formed by radio selected AGNs, the ''lower'' sequence contains mainly optically selected objects. Whereas an apparent ''gap'' between the two sequences may be an artifact of selection effects, the sequences themselves mark the real upper bounds of radio-loudness of two distinct populations of AGNs: those hosted respectively by elliptical and disk galaxies. Both sequences show the same dependence of the radio-loudness on the Eddington ratio (an increase with decreasing Eddington ratio), which suggests that the normalization of this dependence is determined by the black hole spin. This implies that central black holes in giant elliptical galaxies have (on average) much larger spins than black holes in spiral/disc galaxies. This galaxy-morphology related radio-dichotomy breaks down at high accretion rates where the dominant fraction of luminous quasars hosted by elliptical galaxies is radio quiet. This led to speculations in the literature that formation of powerful jets at high accretion rates is intermittent and related to switches between two disk accretion modes, as directly observed in some BH X-ray binaries. We argue that such intermittency can be reconciled with the spin paradigm, provided that successful formation of relativistic jets by rotating black holes requires collimation by MHD outflows from accretion disks.
Download or read book An Introduction to Active Galactic Nuclei written by Bradley M. Peterson and published by Cambridge University Press. This book was released on 1997-02-13 with total page 258 pages. Available in PDF, EPUB and Kindle. Book excerpt: How can we test if a supermassive black hole lies at the heart of every active galactic nucleus? What are LINERS, BL Lacs, N galaxies, broad-line radio galaxies and radio-quiet quasars and how do they compare? This timely textbook answers these questions in a clear, comprehensive and self-contained introduction to active galactic nuclei - for graduate students in astronomy and physics. The study of AGN is one of the most dynamic areas of contemporary astronomy, involving one fifth of all research astronomers. This textbook provides a systematic review of the observed properties of AGN across the entire electromagnetic spectrum, examines the underlying physics, and shows how the brightest AGN, quasars, can be used to probe the farthest reaches of the Universe. This book serves as both an entry point to the research literature and as a valuable reference for researchers in the field.
Download or read book Active Galactic Nuclei written by Volker Beckmann and published by John Wiley & Sons. This book was released on 2013-08-29 with total page 390 pages. Available in PDF, EPUB and Kindle. Book excerpt: Active Galactic Nuclei This AGN textbook gives an overview on the current knowledge of the Active Galacitc Nuclei phenomenon. The spectral energy distribution will be discussed, pointing out what can be observed in different wavebands. The different physical models are presented together with formula important for the understanding of AGN physics. Furthermore, the authors discuss the AGN with respect to its environment, host galaxy, feedback in galaxies and in clusters of galaxies, variability, etc. and finally the cosmological evolution of the AGN phenomenon. This book includes phenomena based on new results in the X-Ray and gamma-ray domain from new telescopes such as Chandra, XMM-Newton, the Fermi Gamma-Ray Space Telescope, and the VHE regime not mentioned so far in AGN books. Those and other new developments as well as simulations of AGN merging events and formations, enabled through latest super-computing capabilities. From the contents: The observational picture of AGN Radiative processes The central engine AGN types and unification AGN through the electromagnetic spectrum AGN variability Environment Quasars and cosmology Formation, evolution and the ultimate fate of AGN What we do not know (yet)
Download or read book The Evolution of Radio loud Active Galactic Nuclei written by Nathan de Vries and published by . This book was released on 2009 with total page 163 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Quasars and Active Galactic Nuclei written by Ajit K. Kembhavi and published by Cambridge University Press. This book was released on 1999-03-11 with total page 488 pages. Available in PDF, EPUB and Kindle. Book excerpt: The latest observations and theoretical models are combined in this clear, pedagogic textbook for advanced undergraduates and graduate students.
Download or read book Active Galactic Nuclei written by Ian Robson and published by Wiley-Blackwell. This book was released on 1996 with total page 420 pages. Available in PDF, EPUB and Kindle. Book excerpt: Understanding the energy source and physical processes within active galaxies are the most challenging areas of current research. Using a logical format and easy-to-follow explanations, Robson demonstrates the crucial connections between observation and theory, illustrating how diverse classes of active galaxies fit into the contemporary perspective. Summary sections explain the physical concepts behind the mathematics.
Download or read book Radio Loudness of AGNs written by and published by . This book was released on 2007 with total page 7 pages. Available in PDF, EPUB and Kindle. Book excerpt: We investigate how the total radio luminosity of AGN-powered radio sources depends on their accretion luminosity and the central black hole mass. We find that AGNs form two distinct and well separated sequences on the radio-loudness -- Eddington-ratio plane. We argue that these sequences mark the real upper bounds of radio-loudness of two distinct populations of AGNs: those hosted respectively by elliptical and disk galaxies. Both sequences show the same dependence of the radio-loudness on the Eddington ratio (an increase with decreasing Eddington ratio), which suggests that another parameter in addition to the accretion rate must play a role in determining the jet production efficiency in active galactic nuclei, and that this parameter is related to properties of the host galaxy. The revealed host-related radio dichotomy breaks down at high accretion rates where the dominant fraction of luminous quasars hosted by elliptical galaxies is radio quiet. We argue that the huge difference between the radio-loudness reachable by AGNs in disc and elliptical galaxies can be explained by the scenario according to which the spin of a black hole determines the outflows power, and central black holes can reach large spins only in early type galaxies (following major mergers), and not (in a statistical sense) in spiral galaxies.
Download or read book The X ray Background written by Xavier Barcons and published by Cambridge University Press. This book was released on 1992-07-31 with total page 328 pages. Available in PDF, EPUB and Kindle. Book excerpt: A review of the current observational knowledge and understanding of the cosmic X-ray background.
Download or read book The Large scale Environments of Radio loud Active Galactic Nuclei and Their Evolution Across Cosmic Time written by Dominika Wylezalek and published by . This book was released on 2014 with total page 148 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Extragalactic Radio Sources written by Jacques Roland and published by Cambridge University Press. This book was released on 1992-06-26 with total page 392 pages. Available in PDF, EPUB and Kindle. Book excerpt: The physics of active galactic nuclei, the origin of extragalactic jets and the formation of extended extragalactic radio sources are among the most interesting challenges of modern astrophysics. This book contains the proceedings of the 7th meeting of the Institut d'Astrophysique de Paris, which drew together both theorists and observers in this exciting field. Recent observational data at X-ray, optical and radio wavelengths is discussed, and new theoretical developments concerning beam and jet formation models are considered. Special treatment is given to plasma physics problems related to particle acceleration, magnetic reconnection, beam-plasma interaction and coherent emission. The volume will be of use to all students and researchers who are working in this field.
Download or read book Active Galactic Nuclei written by Julian H. Krolik and published by Princeton University Press. This book was released on 2021-03-09 with total page 632 pages. Available in PDF, EPUB and Kindle. Book excerpt: This is the first comprehensive treatment of active galactic nuclei--the cosmic powerhouses at the core of many distant galaxies. The term active galactic nuclei refers to quasars, radio galaxies, Seyfert galaxies, blazars, and related objects, all of which are believed to share a similar central engine--a supermassive black hole many times the mass of the Sun. Astrophysicists have studied these phenomena for the past several decades and have begun to develop a consensus about many of their properties and internal mechanisms. Julian Krolik, one of the world's leading authorities on the subject, sums up leading ideas from across the entire range of research, making this book an invaluable resource for astronomers, physicists interested in applications of the theory of gravitation, and graduate students. Krolik begins by addressing basic questions about active galactic nuclei: What are they? How can they be found? How do they evolve? He assesses the evidence for massive black holes and considers how they generate power by accretion. He discusses X-ray and g-ray emission, radio emission and jets, emission and absorption lines, anisotropic appearance, and the relationship between an active nucleus and its host galaxy. He explores the mysteries of what ignites, fuels, and extinguishes active galactic nuclei, and concludes with a general review of where the field now stands. The book is unique in paying careful attention to relevant physics as well as astronomy, reflecting in part the importance of general relativity to understanding active galactic nuclei. Clear, authoritative, and detailed, this is crucial reading for anyone interested in one of the most dynamic areas of astrophysics today.
Download or read book A Multi wavelength Study of Radio loud Active Galactic Nuclei written by Elizabeth J. A. Mannering and published by . This book was released on 2013 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Broad H Alpha Profiles of Radio loud Active Galactic Nuclei and Rapid Profile Variability in Seyfert and Radio Galaxies written by Michael Eracleous and published by . This book was released on 1992 with total page 216 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book The Physics and Evolution of Active Galactic Nuclei written by Hagai Netzer and published by Cambridge University Press. This book was released on 2013-09-16 with total page 369 pages. Available in PDF, EPUB and Kindle. Book excerpt: A comprehensive introduction to the theory underpinning our study of active galactic nuclei and the ways we observe them.
Download or read book Volume 16 How to Detect and Handle Outliers written by Boris Iglewicz and published by Quality Press. This book was released on 1993-01-08 with total page 99 pages. Available in PDF, EPUB and Kindle. Book excerpt: Outliers are the key focus of this book. The authors concentrate on the practical aspects of dealing with outliers in the forms of data that arise most often in applications: single and multiple samples, linear regression, and factorial experiments. Available only as an E-Book.
Download or read book The Phenomenology of Outflows from Radio Loud Active Galactic Nuclei written by Erick Jimenez Guerra and published by . This book was released on 1997 with total page 252 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Multiwavelength Studies of Radio loud Active Galactic Nuclei in the Fermi Era written by Jennifer Ann Gupta and published by . This book was released on 2012 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt:
