Download or read book Radio Structures of a Complete Sample of Quasars written by D. L. Shone and published by . This book was released on 1985 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Radio Structures for a Sample of Quasars Selected at a Frequency of 966 MHz written by Roger George Noble and published by . This book was released on 1978 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Radio Structure in Quasars written by Pieter Dirk Barthel and published by . This book was released on 1984 with total page 200 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 Reprints National Radio Astronomy Observatory Green Bank W Va written by National Radio Astronomy Observatory (U.S.) and published by . This book was released on 1977 with total page 568 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Literature 1978 Part 1 written by S. Böhme and published by Springer Science & Business Media. This book was released on 2013-11-11 with total page 845 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Radio Astronomy and Cosmology written by D.L. Jauncey and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 387 pages. Available in PDF, EPUB and Kindle. Book excerpt: 337 F(e) = (z) where the angle between the directions III and 112 is equal to 8. r is the angular diameter effective distance of the epoch for recombination. F (8) ~ve have F(e) : f (e) ~ (S" ) e. . ~ is a Bessel function. It is assumed here that the spectrum of gravitational waves takes the form 1\ hI'::: hoK for all relevant wavelengths, a is beam width of the radio antenna, d\= d~, and ~ is the duration of the process of recombinations in \-time. The results for different beam widths are shown in Fig. 1. 338 I. D. NOVIKOV 1-. . . -__ 0. 5 1 1. 5 2 e' 0. 5 o and for a l' (solid line) and Fig. 1. The function f(8) for n for a = 2' (dotted line). These formula should be used in analysing the implications of future observations. Comparison with the observational data now available enables us to establish an upper limit for the energy density of long gravitational waves. This method is most sensitive for gravitational waves with A ~ ct The fluctuations ~; due to these waves have scale ~ 0. 03 GW rec 4 radian. If, according to modern observations, we take ~;

Download or read book Extragalactic Radio Sources written by R. Ekers and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 666 pages. Available in PDF, EPUB and Kindle. Book excerpt: On the 100th anniversary of Marconi's successful experiment on radio broadcasting, 250 astronomers from all over the world met in Bologna (Italy) for five days, to update their knowledge of the physics and statistical properties of powerful extragalactic radio sources. Since their discovery in the fifties enormous progress has been made. The existence of superluminal motions in the cores of radio sources, the presence there of a black hole surrounded by an absorbing dust torus, as inferred mostly from studies at other wavelengths, are now accepted ideas. Nevertheless, in spite of these efforts, there are many questions still unanswered. For instance we do not know which mechanism produces the huge amount of energy supplied to radio sources, how the jets connecting the `engine' to the lobes are formed and collimated, which of the differences observed among the various classes of radio sources are apparent and which are real. These and other related topics are discussed in this book.

Download or read book Radio Studies of a Complete Sample of Quasars written by Robert Ira Potash and published by . This book was released on 1986 with total page 145 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 Literature 1979 Part 1 written by Siegfried Böhme and published by Springer Science & Business Media. This book was released on 2013-04-18 with total page 882 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Literature 1997 Part 1 written by Astronomisches Rechen-InstitutARI and published by Springer Science & Business Media. This book was released on 2013-11-11 with total page 1746 pages. Available in PDF, EPUB and Kindle. Book excerpt: Astronomy and Astrophysics Abstracts is devoted to the recording, summarizing and indexing of astronomical publications throughout the world. Two volumes are scheduled to appear per year. Volume 67 records 10,903 papers covering besides the classical fields of astronomy and astrophysics such matters as space flights related to astronomy, lunar and planetary probes and satellites, meteorites and interplanetary matter, X rays and cosmic rays, quasars and pulsars. The abstracts are classified under more than one hundred subject categories thus permitting quick surveying of the bulk of material published on the same topic within six months. For instance, this volume records 119 papers on minor planets, 155 papers on supernovae, and 554 papers on cosmology.

Download or read book Astronomy and Astrophysics Abstracts written by S. Böhme and published by Springer Science & Business Media. This book was released on 2013-12-14 with total page 787 pages. Available in PDF, EPUB and Kindle. Book excerpt: Astronomy and Astrophysics Abstracts, which has appeared in semi-annual volumes since 1969, is devoted to the recording, summarizing and indexing of astronomical publications throughout the world. It is prepared under the auspices of the International Astronomical Union (according to a resolution adopted at the 14th General Assembly in 1970). Astronomy and Astrophysics Abstracts aims to present a comprehensive documenta tion of literature in all fields of astronomy and astrophysics. Every effort will be made to ensure that the average time interval between the date of receipt of the original literature and publication of the abstracts will not exceed eight months. This time interval is near to that achieved by monthly abstracting journals, compared to which our system of accumu lating abstracts for about six months offers the advantage of greater convenience for the user. Volume 31 contains literature published in 1982 and received before July 15, 1982; some older literature which was received late and which is not recorded in earlier volumes is also included. We acknowledge with thanks contributions to this volume by Dr. J. Bouska, Prague, who surveyed journals and publications in Czech and supplied us with abstracts in English .

Download or read book Generation of Cosmological Large Scale Structure written by David N. Schramm and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 331 pages. Available in PDF, EPUB and Kindle. Book excerpt: This volwne is the proceedings of the third school in particle astrophysics that Schramm and Galeotti have organized at Erice. The focus of thirs third school was the Generation of Cosmological Large-Scale Structure. It was held in November of 1996. The fIrst school in the series was on "Gauge Theory and the Early Universe" in May 1986, the second was on "Dark Matter in the Universe" in May 1988. All three schools have been successful under the auspices of the NATO Advanced Study Institute. This volume is thus the third in the series of the proceedings of these schools. The choice of the topic for this third school was natural, since the problem of generating a large-scale structure has become the most pressing problem in cosmology today. In particular, it is this generation of structure that is the interface between astronomical observations and particle models for the early universe. To date, all models for generating structures inevitably require new fundamental physics beyond the standard, SU x SU X U , model of high energy physics. The 3 2 I seeds for generating structures usually invoke unifIcation physics, and the matter needed to clump and form them seems to require particle properties that have not been seen in laboratories to date.

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 An Introduction to Radio Astronomy written by Bernard F. Burke and published by Cambridge University Press. This book was released on 2019-08-22 with total page 545 pages. Available in PDF, EPUB and Kindle. Book excerpt: A thorough introduction to radio astronomy and techniques for students and researchers approaching radio astronomy for the first time.

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.