Download or read book Constraining the high energy emission sources in the environment of supermassive black holes written by Francesco Ursini and published by . This book was released on 2016 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Des trous noirs supermassifs de plusieurs centaines de millions de masses solaires résident au centre de la plupart des galaxies massives. Dans 90% des cas, ces trous noirs sont dans état quiescent, très peu lumineux. Cependant, dans les 10% restant, des processus extrêmement violents sont observés, avec la libération d'énorme quantités d'énergie no- tamment en UV, X et gamma. On observe aussi parfois des jets puissants de matière pouvant s'étendre sur plusieurs centaines de kpc. Le coeur de ces galaxies sont appelés Noyaux Actifs de Galaxie (NAG). Ce sont parmis les objets les plus lumineux de l'univers. L'accrétion de la matière environnante sur le trou noir supermassif central est unanimement reconnue comme la source d'énergie la plus plausible pour expliquer la puissance phénoménale observée. L'énergie gravitationelle serait ainsi en partie libérée dans un disque d'accrétion, sous forme de rayonnement thermique piquant dans l'optique/UV, et en partie rayonnée en X/gamma par une couronne de plasma chaud présente dans l'environnement proche du trou noir.De nombreux phénomènes sont néanmoins encore très mal connus et beaucoup de ques- tions n'ont toujours pas de réponses satisfaisantes: quelles sont la dynamique et la structure des flots d'accrétion et d'éjection dans les NAG? Quels sont les processus radiatifs produisant le rayonnement UV/X? Quelle est l'origine des différentes composantes spectrales présentes dans ces domaines d'énergie? Cette thèse a pour objectif d'apporter de nouvelles contraintes observationnelles pour meux répondre à ces questions. Son originalité réside dans le développement et l'utilisation de modèles réalistes de Comptonisation thermique permettant d'une part de mieux contraindre les propriétés physiques et géométriques des régions d'émission UV/X et d'autre part de mieux comprendre l'origine des différentes composantes spectrales observées. Nous nous sommes notamment intéressés, au cours de cette thèse, à l'excès d'émission X-mou (
Download or read book Current High energy Emission Around Black Holes Proceedings Of The 2nd Kias Astrophysics Workshop written by Heon-young Chang and published by World Scientific. This book was released on 2002-05-24 with total page 355 pages. Available in PDF, EPUB and Kindle. Book excerpt: Black holes exist in galactic nuclei and in some X-ray binaries found in our own galaxy and the large Magellanic Cloud. This volume focuses on astrophysical high-energy emission processes around black holes, and the development of theoretical frameworks for interesting observational results.
Download or read book Very High Energy Emission from Passive Supermassive Black Holes written by Giovanna Pedaletti and published by . This book was released on 2009 with total page 96 pages. Available in PDF, EPUB and Kindle. Book excerpt:
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 High Energy Radiation from Black Holes written by Charles D. Dermer and published by Princeton University Press. This book was released on 2009-09-21 with total page 568 pages. Available in PDF, EPUB and Kindle. Book excerpt: Bright gamma-ray flares observed from sources far beyond our Milky Way Galaxy are best explained if enormous amounts of energy are liberated by black holes. The highest- energy particles in nature--the ultra-high-energy cosmic rays--cannot be confined by the Milky Way's magnetic field, and must originate from sources outside our Galaxy. Understanding these energetic radiations requires an extensive theoretical framework involving the radiation physics and strong-field gravity of black holes. In High Energy Radiation from Black Holes, Charles Dermer and Govind Menon present a systematic exposition of black-hole astrophysics and general relativity in order to understand how gamma rays, cosmic rays, and neutrinos are produced by black holes. Beginning with Einstein's special and general theories of relativity, the authors give a detailed mathematical description of fundamental astrophysical radiation processes, including Compton scattering of electrons and photons, synchrotron radiation of particles in magnetic fields, photohadronic interactions of cosmic rays with photons, gamma-ray attenuation, Fermi acceleration, and the Blandford-Znajek mechanism for energy extraction from rotating black holes. The book provides a basis for graduate students and researchers in the field to interpret the latest results from high-energy observatories, and helps resolve whether energy released by rotating black holes powers the highest-energy radiations in nature. The wide range of detail will make High Energy Radiation from Black Holes a standard reference for black-hole research.
Download or read book The Tidal Disruption of Stars by Supermassive Black Holes written by Nicholas Chamberlain Stone and published by Springer. This book was released on 2014-12-13 with total page 162 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book provides a general introduction to the rapidly developing astrophysical frontier of stellar tidal disruption, but also details original thesis research on the subject. This work has shown that recoiling black holes can disrupt stars far outside a galactic nucleus, errors in the traditional literature have strongly overestimated the maximum luminosity of “deeply plunging” tidal disruptions, the precession of transient accretion disks can encode the spins of supermassive black holes, and much more. This work is based on but differs from the original thesis that was formally defended at Harvard, which received both the Roger Doxsey Award and the Chambliss Astronomy Achievement Student Award from the American Astronomical Society.
Download or read book The Supermassive Black Hole at the Centre of Our Galaxy written by Ecaterina Marion Howard and published by . This book was released on 2015 with total page 233 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Current High energy Emission Around Black Holes written by and published by . This book was released on 2002 with total page 344 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Renewable Energy Sources and Climate Change Mitigation written by Ottmar Edenhofer and published by Cambridge University Press. This book was released on 2011-11-21 with total page 1088 pages. Available in PDF, EPUB and Kindle. Book excerpt: This Intergovernmental Panel on Climate Change Special Report (IPCC-SRREN) assesses the potential role of renewable energy in the mitigation of climate change. It covers the six most important renewable energy sources - bioenergy, solar, geothermal, hydropower, ocean and wind energy - as well as their integration into present and future energy systems. It considers the environmental and social consequences associated with the deployment of these technologies, and presents strategies to overcome technical as well as non-technical obstacles to their application and diffusion. SRREN brings a broad spectrum of technology-specific experts together with scientists studying energy systems as a whole. Prepared following strict IPCC procedures, it presents an impartial assessment of the current state of knowledge: it is policy relevant but not policy prescriptive. SRREN is an invaluable assessment of the potential role of renewable energy for the mitigation of climate change for policymakers, the private sector, and academic researchers.
Download or read book The Multi Messenger Approach to High Energy Gamma Ray Sources written by Josep M. Paredes and published by Springer Science & Business Media. This book was released on 2007-07-17 with total page 496 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book provides a theoretical and observational overview of the state of the art of gamma-ray astrophysics, and their impact and connection with the physics of cosmic rays and neutrinos. With the aim of shedding new and fresh light on the problem of the nature of the gamma-ray sources, particularly those yet unidentified, this book summarizes contributions to a workshop that continues today.
Download or read book Stellar Structure and Evolution written by Rudolf Kippenhahn and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 480 pages. Available in PDF, EPUB and Kindle. Book excerpt: A complete and comprehensive treatment of the physics of the stellar interior and the underlying fundamental processes and parameters. The text presents an overview of the models developed to explain the stability, dynamics and evolution of the stars, and great care is taken to detail the various stages in a star's life. The authors have succeeded in producing a unique text based on their own pioneering work in stellar modeling. Since its publication, this textbook has come to be considered a classic by both readers and teachers in astrophysics. This study edition is intended for students in astronomy and physics alike.
Download or read book Active Galactic Nuclei written by John Edward Dyson and published by Manchester University Press. This book was released on 1985 with total page 404 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Astrophysical Sources of High Energy Particles and Radiation written by Tomasz Bulik and published by American Institute of Physics. This book was released on 2005-12-06 with total page 440 pages. Available in PDF, EPUB and Kindle. Book excerpt: The main purpose of this conference was to present an overview of the current state of research in the area of high energy astrophysics. In particular, the mechanisms of particle acceleration, generation of high energy radiation, and polarization properties of such emission were discussed. A broad range of compact and diffuse sources, ranging from stellar to extragalactic objects are covered.
Download or read book Special Relativity Electrodynamics and General Relativity written by John B. Kogut and published by Academic Press. This book was released on 2018-01-09 with total page 456 pages. Available in PDF, EPUB and Kindle. Book excerpt: Special Relativity, Electrodynamics, and General Relativity: From Newton to Einstein is intended to teach students of physics, astrophysics, astronomy, and cosmology how to think about special and general relativity in a fundamental but accessible way. Designed to render any reader a "master of relativity,” all material on the subject is comprehensible and derivable from first principles. The book emphasizes problem solving, contains abundant problem sets, and is conveniently organized to meet the needs of both student and instructor. Fully revised and expanded second edition with improved figures Enlarged discussion of dynamics and the relativistic version of Newton’s second law Resolves the twin paradox from the principles of special and general relativity Includes new chapters which derive magnetism from relativity and electrostatics Derives Maxwell’s equations from Gauss’ law and the principles of special relativity Includes new chapters on differential geometry, space-time curvature, and the field equations of general relativity Introduces black holes and gravitational waves as illustrations of the principles of general relativity and relates them to the 2015 and 2017 observational discoveries of LIGO
Download or read book High Energy Gamma Ray Astronomy written by F.A. Aharonian and published by AIP Conference Proceedings (Nu. This book was released on 2009-01-15 with total page 940 pages. Available in PDF, EPUB and Kindle. Book excerpt: The fourth in a series of major international conferences in the field of Gamma-Ray Astronomy, attended by leading experts as well as young scientists from many universities and research centers. The symposium covered the basic observational and many theoretical topics related to ground and space-based Gamma-Ray Astronomy, Astroparticle Physics and Cosmology.
Download or read book New Worlds New Horizons in Astronomy and Astrophysics written by National Research Council and published by National Academies Press. This book was released on 2011-02-04 with total page 324 pages. Available in PDF, EPUB and Kindle. Book excerpt: Driven by discoveries, and enabled by leaps in technology and imagination, our understanding of the universe has changed dramatically during the course of the last few decades. The fields of astronomy and astrophysics are making new connections to physics, chemistry, biology, and computer science. Based on a broad and comprehensive survey of scientific opportunities, infrastructure, and organization in a national and international context, New Worlds, New Horizons in Astronomy and Astrophysics outlines a plan for ground- and space- based astronomy and astrophysics for the decade of the 2010's. Realizing these scientific opportunities is contingent upon maintaining and strengthening the foundations of the research enterprise including technological development, theory, computation and data handling, laboratory experiments, and human resources. New Worlds, New Horizons in Astronomy and Astrophysics proposes enhancing innovative but moderate-cost programs in space and on the ground that will enable the community to respond rapidly and flexibly to new scientific discoveries. The book recommends beginning construction on survey telescopes in space and on the ground to investigate the nature of dark energy, as well as the next generation of large ground-based giant optical telescopes and a new class of space-based gravitational observatory to observe the merging of distant black holes and precisely test theories of gravity. New Worlds, New Horizons in Astronomy and Astrophysics recommends a balanced and executable program that will support research surrounding the most profound questions about the cosmos. The discoveries ahead will facilitate the search for habitable planets, shed light on dark energy and dark matter, and aid our understanding of the history of the universe and how the earliest stars and galaxies formed. The book is a useful resource for agencies supporting the field of astronomy and astrophysics, the Congressional committees with jurisdiction over those agencies, the scientific community, and the public.
Download or read book The Physics of Accretion onto Black Holes written by Maurizio Falanga and published by Springer. This book was released on 2014-10-28 with total page 483 pages. Available in PDF, EPUB and Kindle. Book excerpt: Provides a comprehensive summary on the physical models and current theory of black hole accretion, growth and mergers, in both the supermassive and stellar-mass cases. This title reviews in-depth research on accretion on all scales, from galactic binaries to intermediate mass and supermassive black holes. Possible future directions of accretion are also discussed. The following main themes are covered: a historical perspective; physical models of accretion onto black holes of all masses; black hole fundamental parameters; and accretion, jets and outflows. An overview and outlook on the topic is also presented. This volume summarizes the status of the study of astrophysical black hole research and is aimed at astrophysicists and graduate students working in this field. Originally published in Space Science Reviews, Vol 183/1-4, 2014.
