Download or read book AGN Variability from X rays to Radio Waves written by and published by . This book was released on 2006 with total page 292 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book AGN Variability from X rays to Radio Waves written by C. Martin Gaskell and published by Astronomical Society of the Pacific. This book was released on 2006 with total page 336 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Variability of Active Galactic Nuclei written by and published by . This book was released on 1991 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Astrophysics Of Gas Nebulae and Active Galactic Nuclei written by Donald E. Osterbrock and published by University Science Books. This book was released on 2006 with total page 488 pages. Available in PDF, EPUB and Kindle. Book excerpt: Thoroughly revised and expanded throughout, the new edition is a graduate-level text and reference book on gaseous nebulae, nova and supernova remnants. Much of the new data and new images are from the Hubble Space Telescope with two wholly new chapters being added along with other new features. The previous edition which was tried and tested for thirty years has now been succeeded by a revised, updated, larger edition, which will be valuable to anyone seriously interested in astrophysics.
Download or read book Lessons from High energy Studies of AGN written by Mario Sanfrutos Carreras and published by . This book was released on 2016 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: This is a doctoral dissertation about the X–ray observational and theoretical study of active galactic nuclei (AGN). In the following paragraphs, the research lines addressed during my Ph. D. work are exposed. From a theoretical approach, my work belongs to the supermassive black hole (SMBH) + accretion disc paradigm for AGN. Material within the geometrically thin, optically thick disc, accretes onto the black hole, dissipating a significant amount of energy in its innermost regions due to viscous tensions. This energy is dissipated as energetic photons, most in the ultraviolet (UV) range, which gain energy in their interaction with very hot, free electrons near the disc, up to reaching the X– ray wavelength. This process is referred to as inverse Compton upscattering. The primary X–ray source is called “corona”, by analogy with the X–ray–emitting region in the Sun. Irradiation of the accretion disc by those X–rays, yields a characteristic reflection spectrum, and the fluorescent emission lines (being the FeK the most important of them). Hence, an intrincate blend of at least two spectral components is detected by our observatories in orbit: unprocessed X–rays (the so– called “continuum”, emitted by the corona), and reprocessed X–rays (result of the reflection of the continuum in the irradiated material, namely the accretion disc and the torus inner boundaries). Both components are relativistically blurred due to the proximity of the X–ray sources to the black hole. The relativistid effects involved in this process are: Doppler boosting, aberration, light bending and gravitational redshift. From an observational point of view, given the facts stated in the upper paragraph, the spectral features of each observation (especially, the relativistic iron line profile), carry valuable information of the innermost regions of AGN. Also, light curves analyses shed light on AGN intrinsic variability, providing additional information about the mechanisms producing the X–rays, about the properties of the different spectral components, and about the geometry of the emitting regions. In this regard, the interesting objects for this dissertation are unobscured AGN, i.e., those AGN that allow a direct view of their innermost regions, with the so–called “torus” of the Unification models not blocking our line of sight (LOS) to the nucleus. The data used in this thesis are both proprietary and from the XMM–Newton and Chandra archives...
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 Variability of Active Galactic Nuclei written by Hugh Richard Miller and published by . This book was released on 1991 with total page 387 pages. Available in PDF, EPUB and Kindle. Book excerpt: Active galactic nuclei (AGN), the most powerful objects in the universe, continue to receive a great deal of attention from observational astronomers & theorists. This book collects the results presented at a meeting held at Georgia State University in May 1990 on the topic of variability in active galactic nuclei. It is clear that careful analysis of variability over many wave bands is likely to give clues to the nature of the central engine in AGN. The contributions are grouped in themes: multifrequency variability, UV-optical-IR variability, radio variability, & X-ray variability. One of the most exciting results reported here is that many blazars exhibit micro-variability. There is an important group of papers on NGC 5548 & other Seyfert galaxies. The meeting in Atlanta provided the first opportunity for discussion for those who participated in the worldwide campaign to observe NGC 5548, & new results are also announced for many quasars, Seyfert galaxies, BL Lacertae objects, & radio galaxies. The observational data are interspersed with theoretical insights that enable us to better understand the physical conditions & processes in galactic nuclei, including giant black holes thought to lurk in their cores.
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 Massive Stars in Starbursts written by Claus Leitherer and published by Cambridge University Press. This book was released on 1991-05-16 with total page 354 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book reviews the importance of massive stars in several areas of astrophysics. Massive stars are objects that are 10-100 times the mass of our Sun. Above ten solar masses, loss through stellar winds begins to have a major impact on the evolution of a star. The upper limit of 100 solar masses is derived from observations. Significant progress has now been achieved in massive star research. New models, along with high quality observations, have improved our understanding of the formation, structure, atmosphere, and evolution of these massive objects. They are formed in violent bursts of star formation and are probably related to the phenomena observed in active galactic nuclei. The workshop at the Space Telescope Science Institute examined the interplay between the astrophysics of massive stars and their location in extragalactic starburst regions. There are eighteen chapters by leading researchers. Each has been carefully edited to ensure that the book is a comprehensive introduction to the theory and observation of massive stars in starburst regions.
Download or read book High Energy Astrophysics written by Malcolm S. Longair and published by Cambridge University Press. This book was released on 2011-02-03 with total page 885 pages. Available in PDF, EPUB and Kindle. Book excerpt: Providing students with an in-depth account of the astrophysics of high energy phenomena in the Universe, the third edition of this well-established textbook is ideal for advanced undergraduate and beginning graduate courses in high energy astrophysics. Building on the concepts and techniques taught in standard undergraduate courses, this textbook provides the astronomical and astrophysical background for students to explore more advanced topics. Special emphasis is given to the underlying physical principles of high energy astrophysics, helping students understand the essential physics. The third edition has been completely rewritten, consolidating the previous editions into one volume. It covers the most recent discoveries in areas such as gamma-ray bursts, ultra-high energy cosmic rays and ultra-high energy gamma rays. The topics have been rearranged and streamlined to make them more applicable to a wide range of different astrophysical problems.
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 X ray Studies of the Central Engine in Active Galactic Nuclei with Suzaku written by Hirofumi Noda and published by Springer. This book was released on 2015-12-07 with total page 164 pages. Available in PDF, EPUB and Kindle. Book excerpt: The aim of this research was to use the X-ray satellite Suzaku to establish a picture of a central engine that effectively converts the gravitational energy of accreting matter onto the supermassive black hole to a huge amount of radiation in an active galactic nucleus. Although the engine is known to consist of a Comptonizing corona and an accretion disk, its image has remained unclear because primary emissions, coming directly from the engine, cannot be identified in X-ray spectra without models. The book describes a technique of time variability assisted spectral decomposition to model-independently examine X-ray signals, and how this was applied to the Suzaku archive data of active galactic nuclei. As a result, at least three distinct primary X-ray components have been discovered in an X-ray from an active galactic nucleus, presumably indicating a novel picture that the engine is composed of multiple coronae with different physical properties in an accretion flow. Furthermore, the determination of the spectral shapes of the primary X-rays has a significant impact on estimations of black hole spins, because it is essential to quantify reprocessed X-ray spectra. The successful model-independent decomposition of X-ray spectral components with flux variations of active galactic nuclei is likely to be effective in future data analyses from the soon-to-be-launched Japanese X-ray satellite ASTRO-H, which is capable of achieving unprecedented fine spectros copy and broad energy band coverage.
Download or read book Advanced Topics on Astrophysical and Space Plasmas written by E.M. de Gouveia Dal Pino and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 298 pages. Available in PDF, EPUB and Kindle. Book excerpt: In June of 1996, at the idyllic seaside resort of Guarujá, Brazil, a renowned group of researchers in space and astrophysical plasmas met to provide a forum on Advanced Topics on Astrophysical and Space Plasmas at a school consisting of some 60 students and teachers, mainly from Brazil and Argentina, but also from all the other parts of the globe. The purpose was to provide an update on the latest theories, observations, and simulations of space-astrophysical plasma phenomena. The topics covered included space plasma mechanisms for particle acceleration, nonthermal emission in cosmic plasma, magnetohydrodynamic instabilities in solar, interstellar, and other cosmic objects, magnetic field line reconnection and merging, the nonlinear and often chaotic structure of astrophysical plasmas, and the advances in high performance supercomputing resources to replicate the observed phenomena. The lectures were presented by Professor Mark Birkinshaw of the Harvard-Smithsonian Center for Astrophysics and the University of Bristol; Dr Anthony Peratt, Los Alamos National Laboratory Scientific Advisor to the United States Department of Energy; Dr Dieter Biskamp of the Max Planck Institute for Plasma Physics, Garching, Germany; Professor Donald Melrose, Director, Centre for Theoretical Astrophysics, University of Sydney, Australia; Professor Abraham Chian of the National Institute for Space Research, Brazil; and Professor Nelson Fiedler-Ferrara of the University of São Paulo, Brazil. As summarized by Professor Reuven Opher, Institute of Astronomy and Geophysics, University of São Paulo, the advanced or interested student of space and astrophysical plasmas will find reference to nearly all modern aspects in the field of Plasma Astrophysics and Cosmology in the presented lectures.
Download or read book Variability of Blazars written by E. VALTAOJA (Ed) and published by Cambridge University Press. This book was released on 1992 with total page 484 pages. Available in PDF, EPUB and Kindle. Book excerpt: Blazars (also known as BL Lac objects), first discovered in 1978, are unusually energetic objects in the extragalactic universe. About 200 are known or suspected. They are radio sources with highly variable optical and radio emission, as well as high polarisation, and their optical spectra normally have no distinguishable features. It is generally accepted that they belong to that class of galaxies with active galactic nuclei, which are presumed to be driven by infall of matter to a supermassive black hole. In this book researchers give a complete summary of the observations of blazars and the theoretical interpretation. A comprehensive listing of confirmed and candidate objects is included. Mechanisms in which the variability can arise from shocks and relativistic jets are discussed. There are at least four different answers given to the question: what is a blazar? This book is a complete overview of the violent activity observed in these extreme active galactic nuclei.
Download or read book The High Radio Frequency Variability of AGN written by Markku Lainela and published by . This book was released on 1993 with total page 27 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Fifty Years of Quasars written by Mauro D'Onofrio and published by Springer Science & Business Media. This book was released on 2012-09-14 with total page 613 pages. Available in PDF, EPUB and Kindle. Book excerpt: The 50th anniversary of the discovery of quasars in 1963 presents an interesting opportunity to ask questions about the current state of quasar research. Formatted as a series of interviews with noted researchers in the field, each of them asked to address a specific set of questions covering topics selected by the editors, this book deals with the historical development of quasar research and discusses how advances in instrumentation and computational capabilities have benefitted quasar astronomy and have changed our basic understanding of quasars. In the last part of the book the interviews address the current topic of the role of quasars in galaxy evolution. They summarise open issues in understanding active galactic nuclei and quasars and present an outlook regarding what future observational facilities both on the ground and in space might reveal. Its interview format, the fascinating topic of quasars and black holes, and the lively recollections and at times controversial views of the contributors make this book both rewarding and a pleasure to read!
Download or read book The Nature of Compact Objects in Active Galactic Nuclei written by Andrew Robinson and published by Cambridge University Press. This book was released on 1994-03-03 with total page 466 pages. Available in PDF, EPUB and Kindle. Book excerpt: What evidence is there for and against unified schemes for active galactic nuclei (AGN)? How do the AGN populations evolve over cosmological timescales? And what can the variability of their UV and X-ray emission tell us? These are just some of the exciting issues addressed in this volume of papers collected from the 33rd Herstmonceux conference in Cambridge. AGN are among the most spectacular objects known to astronomy. Yet, despite years of intense and wide-ranging research, the debate continues - what is their fundamental source of power? Rapid progress has been made towards answering this question by a variety of large-scale, multi-wavelength monitoring campaigns and the latest generation of satellite-borne observations. This volume provides a valuable overview and timely update of the exciting and rapidly developing field of AGN research - essential reading for graduate students and researchers.
