Download or read book On the Nature of Emission Line Clouds of Quasars and Active Galactic Nuclei written by Demosthenes Kazanas and published by . This book was released on 1989 with total page 46 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Structure and Kinematics of Quasar Broad Line Regions written by C. Martin Gaskell and published by . This book was released on 1999 with total page 480 pages. Available in PDF, EPUB and Kindle. Book excerpt: Annotation Proceedings of a March 1998 meeting, with papers in sections on general considerations and photoionization modeling, profile variation and reverberation mapping, flows, disks, narrow-line Seyfert 1 galaxies, the intermediate line region and lower-velocity gas, X-ray warm absorber and dust, and unified theories and connections with extended emission. Specific topics include spectral variability of NGC 4151 during 1990 and disk emission line issues. Lacks a subject index. The editor is associated with the University of Nebraska. Annotation c. Book News, Inc., Portland, OR (booknews.com)
Download or read book Active Galactic Nuclei written by Hugh Richard Miller and published by Springer. This book was released on 1988-07-13 with total page 460 pages. Available in PDF, EPUB and Kindle. Book excerpt: This volume summarizes recent developments in our understanding of active galactic nuclei, including quasars, seyfert galaxies and radio galaxies. The predominant emphasis is put on observational results with information from essentially all wave bands, but important theoretical results are also presented. Among the contributions are discussions of the different types of active galaxies, the nature of the central engine, the wiggly structure of radio jets, the dynamics of the gas in jets, the study of millimeter and extreme ultraviolet regions, and a discussion of the observed continuum of the entire electromagnetic spectrum. The intended readers are professional astronomers and astrophysicists as well as graduate students in this field of research.
Download or read book The Kinematics of the Emission Line Gas in Quasars and Active Galactic Nuclei written by Timothy John Carroll and published by . This book was released on 1984 with total page 270 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Quasars at All Cosmic Epochs written by Paola Marziani and published by Frontiers Media SA. This book was released on 2018-10-05 with total page 447 pages. Available in PDF, EPUB and Kindle. Book excerpt: The last 50 years have seen a tremendous progress in the research on quasars. From a time when quasars were unforeseen oddities, we have come to a view that considers quasars as active galactic nuclei, with nuclear activity a coming-of-age experienced by most or all galaxies in their evolution. We have passed from a few tens of known quasars of the early 1970s to the 500,000 listed in the catalogue of the Data Release 14 of the Sloan Digital Sky Survey. Not surprisingly, accretion processes on the central black holes in the nuclei of galaxies — the key concept in our understanding of quasars and active nuclei in general — have gained an outstanding status in present-day astrophysics. Accretion produces a rich spectrum of phenomena in all bands of the electromagnetic spectrum. The power output of highly-accreting quasars has impressive effects on their host galaxies. All the improvement in telescope light gathering and in computing power notwithstanding, we still miss a clear connection between observational properties and theory for quasars, as provided, for example, by the H-R diagram for stars. We do not yet have a complete self-consistent view of nuclear activity with predictive power, as we do for main-sequence stellar sources. At the same time quasars offer many “windows open onto the unknown". On small scales, quasar properties depend on phenomena very close to the black hole event horizon. On large scales, quasars may effect evolution of host galaxies and their circum-galactic environments. Quasars’ potential to map the matter density of the Universe and help reconstruct the Universe’s spacetime geometry is still largely unexploited. The times are ripe for a critical assessment of our present knowledge of quasars as accreting black holes and of their evolution across the cosmic time. The foremost aim of this research topic is to review and contextualize the main observational scenarios following an empirical approach, to present and discuss the accretion scenario, and then to analyze how a closer connection between theory and observation can be achieved, identifying those aspects of our understanding that are still on a shaky terrain and are therefore uncertain knowledge. This research topic covers topics ranging from the nearest environment of the black hole, to the environment of the host galaxies of active nuclei, and to the quasars as markers of the large scale structure and of the geometry of spacetime of the Universe. The spatial domains encompass the accretion disk, the emission and absorption regions, circum-nuclear starbursts, the host galaxy and its interaction with other galaxies. Systematic attention is devoted to some key problems that remain outstanding and are clearly not yet solved: the existence of two quasar classes, radio quiet and radio loud, and in general, the systematic contextualization of quasar properties the properties of the central black hole, the dynamics of the accretion flow in the inner parsecs and the origin of the accretion matter, the quasars’ small and large scale environment, the feedback processes produced by the black hole into the host galaxy, quasar evolutionary patterns from seed black holes to the present-day Universe, and the use of quasars as cosmological standard candles. The timing is appropriate as we are now witnessing a growing body of results from major surveys in the optical, UV X, near and far IR, and radio spectral domains. Radio instrumentation has been upgraded to linear detector — a change that resembles the introduction of CCDs for optical astronomy — making it possible to study radio-quiet quasars at radio frequencies. Herschel and ALMA are especially suited to study the circum-nuclear star formation processes. The new generation of 3D magnetohydrodynamical models offers the prospective of a full physical modeling of the whole quasar emitting regions. At the same time, on the forefront of optical astronomy, applications of adaptive optics to long-slit spectroscopy is yielding unprecedented results on high redshift quasars. Other measurement techniques like 2D and photometric reverberation mapping are also yielding an unprecedented amount of data thanks to dedicated experiments and instruments. Thanks to the instrumental advances, ever growing computing power as well as the coming of age of statistical and analysis techniques, the smallest spatial scales are being probed at unprecedented resolution for wide samples of quasars. On large scales, feedback processes are going out of the realm of single-object studies and are entering into the domain of issues involving efficiency and prevalence over a broad range of cosmic epochs. The Research Topic "Quasars at all Cosmic Epochs" collects a large fraction of the contributions presented at a meeting held in Padova, sponsored jointly by the National Institute for Astrophysics, the Padova Astronomical Observatory, the Department of Physics and Astronomy of the University of Padova, and the Instito de Astrofísica de Andalucía (IAA) of the Consejo Superiór de Investigación Cientifica (CSIC). The meeting has been part of the events meant to celebrate the 250th anniversary of the foundation of the Padova Observatory.
Download or read book Galaxies in Turmoil written by C. R. Kitchin and published by Springer Science & Business Media. This book was released on 2007-11-27 with total page 302 pages. Available in PDF, EPUB and Kindle. Book excerpt: Astronomers' Universe Series is a new series aimed at active amateur astronomers but is appropriate to a wider audience of astronomically-informed readers. The book provides an up-to-date account of active galaxies. Lists of such objects and their visual and imaged appearance in commercially available telescopes are an important component of this book. The book makes sense of the chaotic and apparently innumerable types of violently active galaxies. It provides the data and teaches the skills needed for users of small telescopes to observe and image some of these "galaxies in turmoil" for themselves.
Download or read book Galaxies and Cosmology written by Francoise COMBES and published by Springer Science & Business Media. This book was released on 2004-08-11 with total page 468 pages. Available in PDF, EPUB and Kindle. Book excerpt: Unique in its breadth of coverage and level of presentation, this revised textbook provides more on the nature of galaxies, extragalactic objects, the large-scale structure of the Universe, and cosmology than is available in general textbooks on astronomy. It remains, however, accessible to advanced undergraduate students. One or more chapters are devoted to each of the following: the classification and morphology of galaxies; the galactic interstellar medium; galactic kinematics; elliptical, spiral, and barred spiral galaxies; the interactions between galaxies; extragalactic radio sources, quasars and their line spectra, and other active galactic nuclei; the formation of galaxies; the Universe as a whole; and cosmology.
Download or read book Active Galactic Nuclei Mergers and Outflows written by Robert Scott Barrows and published by . This book was released on 2013 with total page 362 pages. Available in PDF, EPUB and Kindle. Book excerpt: I have investigated the nature of a subset of active galactic nuclei (AGN) which show double peaks in their characteristic optical and ultraviolet emission lines. I have performed this investigation through studies of the broad emission line regions (BLRs), which are produced less than 1 pc from the central supermassive black hole (SMBH), and the narrow emission line regions (NLRs), which originate at larger (kpc) distances. The BLR studies consist of detailed line modeling of two individual quasars with double-peaked broad emission line profiles. The modeling suggests there are two primary interpretations of the complex broad line profiles. The first possiblity is line emission from the surface of an asymmetric and/or non-uniform accretion disk of a low-accretion rate AGN; these sources are known as double-peaked emitters and account for only about 3% of the quasar population. The second possibility is line emission from the BLRs of two actively accreting SMBHs in a close (
Download or read book Physics of Active Galactic Nuclei written by Wolfgang J. Duschl and published by Springer. This book was released on 1992 with total page 744 pages. Available in PDF, EPUB and Kindle. Book excerpt:
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.
Download or read book Quasars and Black Holes written by and published by . This book was released on 2013 with total page 64 pages. Available in PDF, EPUB and Kindle. Book excerpt: "An introduction to quasars and black holes with information about their formation and characteristics. Includes diagrams, fun facts, a glossary, a resource list, and an index"--Provided by publisher.
Download or read book Reverberation Mapping of the Broad line Region in Active Galactic Nuclei written by Rutherford Appleton Laboratory. Workshop on Astronomy and Astrophysics and published by . This book was released on 1994 with total page 410 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book The Nature of Emission line Profile Variability and the Structure of the Line emitting Regions in Active Galactic Nuclei written by Kirk Thomas Korista and published by . This book was released on 1990 with total page 422 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Cosmic Rays at Earth written by P.K.F. Grieder and published by Elsevier. This book was released on 2001-07-27 with total page 1117 pages. Available in PDF, EPUB and Kindle. Book excerpt: In 1912 Victor Franz Hess made the revolutionary discovery that ionizing radiation is incident upon the Earth from outer space. He showed with ground-based and balloon-borne detectors that the intensity of the radiation did not change significantly between day and night. Consequently, the sun could not be regarded as the sources of this radiation and the question of its origin remained unanswered. Today, almost one hundred years later the question of the origin of the cosmic radiation still remains a mystery.Hess' discovery has given an enormous impetus to large areas of science, in particular to physics, and has played a major role in the formation of our current understanding of universal evolution. For example, the development of new fields of research such as elementary particle physics, modern astrophysics and cosmology are direct consequences of this discovery. Over the years the field of cosmic ray research has evolved in various directions: Firstly, the field of particle physics that was initiated by the discovery of many so-called elementary particles in the cosmic radiation. There is a strong trend from the accelerator physics community to reenter the field of cosmic ray physics, now under the name of astroparticle physics. Secondly, an important branch of cosmic ray physics that has rapidly evolved in conjunction with space exploration concerns the low energy portion of the cosmic ray spectrum. Thirdly, the branch of research that is concerned with the origin, acceleration and propagation of the cosmic radiation represents a great challenge for astrophysics, astronomy and cosmology. Presently very popular fields of research have rapidly evolved, such as high-energy gamma ray and neutrino astronomy. In addition, high-energy neutrino astronomy may soon initiate as a likely spin-off neutrino tomography of the Earth and thus open a unique new branch of geophysical research of the interior of the Earth. Finally, of considerable interest are the biological and medical aspects of the cosmic radiation because of it ionizing character and the inevitable irradiation to which we are exposed. This book is a reference manual for researchers and students of cosmic ray physics and associated fields and phenomena. It is not intended to be a tutorial. However, the book contains an adequate amount of background materials that its content should be useful to a broad community of scientists and professionals. The present book contains chiefly a data collection in compact form that covers the cosmic radiation in the vicinity of the Earth, in the Earth's atmosphere, at sea level and underground. Included are predominantly experimental but also theoretical data. In addition the book contains related data, definitions and important relations. The aim of this book is to offer the reader in a single volume a readily available comprehensive set of data that will save him the need of frequent time consuming literature searches.
Download or read book Active Galactic Nuclei written by Professor R. D. Blandford and published by Springer. This book was released on 2013-12-14 with total page 289 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Stability of Emission Line Clouds in Active Galactic Nuclei written by Irwin S. Krinsky and published by . This book was released on 1989 with total page 312 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!
