Download or read book Association Between Galaxies and Distant Quasars written by Lucyna Kedziora-Chudczer and published by . This book was released on 1992 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Associations Between Galaxies and Distant Quasars written by Lucyna Kedziora-Chudczer and published by . This book was released on 1992 with total page 198 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Quasars Redshifts and Controversies written by Halton C. Arp and published by Cambridge University Press. This book was released on 1988-09-29 with total page 220 pages. Available in PDF, EPUB and Kindle. Book excerpt: Contests the 'establishment' view of quasars as the most distant objects in the universe.
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 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 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 In Quest of Quasars written by Ben Bova and published by . This book was released on 1969 with total page 216 pages. Available in PDF, EPUB and Kindle. Book excerpt: Defines quasars and what they reveal about the nature of the universe.
Download or read book Joint Evolution of Black Holes and Galaxies written by M. Colpi and published by CRC Press. This book was released on 2006-01-27 with total page 488 pages. Available in PDF, EPUB and Kindle. Book excerpt: Black holes are among the most mysterious objects that the human mind has been capable of imagining. As pure mathematical constructions, they are tools for exploiting the fundamental laws of physics. As astronomical sources, they are part of our cosmic landscape, warping space-time, coupled to the large-scale properties and life cycle of their host galaxy, and perhaps even linked to galaxy formation. This volume, which grew from a recent doctoral school sponsored by the Italian Society of Relativity and Gravitation, brings together contributions from leading authorities to provide a review of recent developments in the study of the astrophysical black holes that inhabit nearby galaxies and distant quasars. These lectures reveal the deep symbiotic relationship between black holes and their cosmic environment and show that black holes are key sources for exploring not only our local universe, but also our cosmic dawn. Topics range from the observational evidence for supermassive black holes and the joint evolution of black holes and galaxies to the cold dark matter paradigm of hierarchical galaxy formation and from the cosmic history of the diffuse intergalactic medium to the ecology of black holes in star clusters.
Download or read book Supermassive Black Holes in the Distant Universe written by A.J. Barger and published by Springer Science & Business Media. This book was released on 2013-11-09 with total page 310 pages. Available in PDF, EPUB and Kindle. Book excerpt: Quasars, and the menagerie of other galaxies with "unusual nuclei", now collectively known as Active Galactic Nuclei or AGN, have, in one form or another, sparked the interest of astronomers for over 60 years. The only known mechanism that can explain the staggering amounts of energy emitted by the innermost regions of these systems is gravitational energy release by matter falling towards a supermassive black hole --- a black hole whose mass is millions to billions of times the mass of our Sun. AGN emit radiation at all wavelengths. X-rays originating at a distance of a few times the event horizon of the black hole are the emissions closest to the black hole that we can detect; thus, X-rays directly reveal the presence of active supermassive black holes. Oftentimes, however, the supermassive black holes that lie at the centers of AGN are cocooned in gas and dust that absorb the emitted low energy X-rays and the optical and ultraviolet light, hiding the black hole from view at these wavelengths. Until recently, this low-energy absorption presented a major obstacle in observational efforts to map the accretion history of the universe. In 1999 and 2000, the launches of the Chandra and XMM-Newton X-ray Observatories finally broke the impasse. The impact of these observatories on X-ray astronomy is similar to the impact that the Hubble Space Telescope had on optical astronomy. The astounding new data from these observatories have enabled astronomers to make enormous advances in their understanding of when accretion occurs.
Download or read book Literature 1981 Part 1 written by Siegfried Böhme and published by Springer Science & Business Media. This book was released on 2013-11-11 with total page 862 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Galaxies and How to Observe Them written by Wolfgang Steinicke and published by Springer Science & Business Media. This book was released on 2007-01-04 with total page 256 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book is a unique work satisfying the need for a modern, comprehensive review of all major aspects of galaxy observation. The book combines the physical background on the nature and data of galaxies, the relevant instrumentation and viewing techniques, and finally the targets and their individual appearance in telescopes of various apertures. A comprehensive sample of galaxies, including quasars, groups and clusters of galaxies is presented. This combination of theoretical knowledge and practical information guarantees successful observing sessions. Furthermore, the book is clearly structured with outstanding images and graphics.
Download or read book External Galaxies and Quasi Stellar Objects written by International Astronomical Union and published by Springer Science & Business Media. This book was released on 1972 with total page 574 pages. Available in PDF, EPUB and Kindle. Book excerpt: Proceedings of IAU Symposium No. 44 held in Uppsala, Sweden, August 10-14, 1970
Download or read book Wide Field Spectroscopy And The Distant Universe Proceedings Of The 35th Herstmonceux Conference written by S Maddox and published by World Scientific. This book was released on 1995-05-31 with total page 438 pages. Available in PDF, EPUB and Kindle. Book excerpt: Galaxies represent the most readily visible fabric of the cosmos. Their morphological types, luminosities and environmental surroundings contain valuable clues as to their origin and evolution. Locally, a strong correlation is seen between galaxy morphology and environmental location; this may have been molded at surprisingly modest redshifts. Spectroscopic and photometric studies of deep fields also suggest remarkably recent changes in the galaxy population. The associated growth of structure during the same interval can be tracked via X-ray studies of distant clusters of galaxies.Very recently, impressive observational facilities have been completed, each of which has extended the astronomers' dataset to look-back times where such evolutionary effects can be studied.This volume discusses surveys which share a common theme — the need for a large number of ground-based spectra. It focuses on the various approaches via a single theme concerned with the evolution of galaxies and their distribution. In the near future, impressive new observational facilities will be able to generate large statistical spectroscopic surveys, and the aim of this volume is to assess the scientific impact that ongoing and future spectroscopic surveys can make. Emphasis is placed on the role of non-optical and satellite facilities and the co-ordination of international efforts.
Download or read book Death from the Skies written by Philip C. Plait and published by Penguin. This book was released on 2008 with total page 338 pages. Available in PDF, EPUB and Kindle. Book excerpt: It's only a matter of time before a cosmic disaster spells the end of the Earth. But how concerned should we about about any of these catastrophic scenarios? And if they do post a danger, can anything be done to stop them?
Download or read book Study of a Possible Correlation Between Quasi stellar Objects and Rich Clusters of Galaxies written by Juan Antonio Castro and published by . This book was released on 1971 with total page 224 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Galaxy Distances and Deviations from Universal Expansion written by Barry F. Madore and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 306 pages. Available in PDF, EPUB and Kindle. Book excerpt: It was a general feeling among those who attended the NATO / ARW meeting on the Galaxy Distances and Deviations from Universal Expansion, that during the week in Hawaii a milestone had been passed in work on the distance scale. While not until the last minute did most of the participants know who else would be attending, no one was displeased with the showing. As it turned out, scarcely a single active worker in the field of the distance scale missed the event. Few knew all of the outstanding work that was to be revealed, and/or the long-term programs that were to be encapsulated in the first few days. Areas of general agreement were pinpointed with candid speed, and most of the discussion moved on quickly to new data, and areas deserving special new attention. As quickly as one project was reported as being brought successfully to a close, a different group would report on new discoveries with new directions to go. New data, new phenomena; but the sentiment was that we were building on a much safer foundation, even if the Universe was unfolding in a much more complex and unexpected way than was previously anticipated. In editing these proceedings a decision was made well in advance of the Meet ing that no attempt would made to record the discussion. This was done for many reasons.
Download or read book Galaxy Formation and Evolution written by Hyron Spinrad and published by Springer Science & Business Media. This book was released on 2006-08-29 with total page 202 pages. Available in PDF, EPUB and Kindle. Book excerpt: An Astronomical Life – Observing the Depths of the Universe” Though science as a subject can be di?cult, what has been more important for me is that its practice can also be rewarding fun! This book is crafted to expose the reader to the excitement of modern observational cosmology through the study of galaxy evolution over space and cosmic time. Recent extragalactic research has led to many rapid advances in the ?eld. Even a suitable skeptic of certain pronouncements about the age and structure of the Universe should be pleased with the large steps that have been taken in furthering our understanding of the Universe since the early 1990’s. My personal involvement in galaxy research goes back to the 1960’s. At that point, galaxies were easily recognized and partially understood as organized c- lections of stars and gas. What their masses were presented a problem, which I supposed would just fade away. But fade it didn’t. Distant active nuclei and quasars were discovered in the mid-1960’s. A c- mon view of QSOs was that they have large redshifts, but what use are they for cosmology or normal galaxy astrophysics? I shared that conclusion. My expec- tions fell below their potential utility. In short, the Universe of our expectations rarely matches the Universe as it is discovered.
