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 High Energy Processes Around the Accretion Disk of AGN written by and published by . This book was released on 1996 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book NgVLA written by Eric James Murphy and published by . This book was released on 2018 with total page 830 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Radiative Processes in High Energy Astrophysics written by Gabriele Ghisellini and published by Springer. This book was released on 2013-06-03 with total page 152 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book grew out of the author’s notes from his course on Radiative Processes in High Energy Astrophysics. The course provides fundamental definitions of radiative processes and serves as a brief introduction to Bremsstrahlung and black body emission, relativistic beaming, synchrotron emission and absorption, Compton scattering, synchrotron self-compton emission, pair creation and emission. The final chapter discusses the observed features of Active Galactic Nuclei and their interpretation based on the radiative processes presented in the book. Written in an informal style, this book will guide students through their first encounter with high-energy astrophysics.
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 2004-08-03 with total page 322 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 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 Neutrino Astronomy Current Status Future Prospects written by Thomas K Gaisser and published by World Scientific. This book was released on 2017-03-20 with total page 251 pages. Available in PDF, EPUB and Kindle. Book excerpt: This review volume is motivated by the recent discovery of high-energy astrophysical neutrinos by IceCube. The aim of the book is to bring together chapters on the status of current and future neutrino observatories with chapters on the implications and possible interpretations of the present observations and their upper limits. Each chapter is a mini-review of one aspect of the subject by leading experts. Taken together, the chapters constitute an up-to-date review of high-energy astrophysical neutrinos and their potential sources.
Download or read book Active Galactic Nuclei written by Francoise Combes and published by John Wiley & Sons. This book was released on 2022-08-23 with total page 324 pages. Available in PDF, EPUB and Kindle. Book excerpt: All galaxies host a super-massive black hole in their center. These black holes grow their mass in symbiosis with their host galaxy and moderate their star formation. When matter is driven towards the nucleus, an accretion disk is formed to transfer angular momentum and considerable energy is released when the material falls into the black hole: this is the phenomenon of active galactic nuclei (AGN). A nucleus can shine one thousand times more brightly than the entire galaxy with its 200 billion stars. The nuclear activity can take many forms, from very powerful quasars to more ordinary Seyfert galaxies, passing by radio-galaxies, which eject a collimated plasma at ten times the radius of the galaxy. This book examines all of these manifestations and presents a unified view. When two galaxies merge, a binary black hole is formed and the two black holes will spiral inwards and merge, emitting long gravitational waves, which could be detected by the future LISA satellite.
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 Energy Research Abstracts written by and published by . This book was released on 1990 with total page 834 pages. Available in PDF, EPUB and Kindle. Book excerpt:
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 Particle Astrophysics and Cosmology written by M.M. Shapiro and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 173 pages. Available in PDF, EPUB and Kindle. Book excerpt: Proceedings of the NATO Advanced Study Institute, Erice, Sicily, Italy, June 20-30, 1992
Download or read book Active Galactic Nuclei written by Francoise Combes and published by John Wiley & Sons. This book was released on 2022-09-21 with total page 324 pages. Available in PDF, EPUB and Kindle. Book excerpt: All galaxies host a super-massive black hole in their center. These black holes grow their mass in symbiosis with their host galaxy and moderate their star formation. When matter is driven towards the nucleus, an accretion disk is formed to transfer angular momentum and considerable energy is released when the material falls into the black hole: this is the phenomenon of active galactic nuclei (AGN). A nucleus can shine one thousand times more brightly than the entire galaxy with its 200 billion stars. The nuclear activity can take many forms, from very powerful quasars to more ordinary Seyfert galaxies, passing by radio-galaxies, which eject a collimated plasma at ten times the radius of the galaxy. This book examines all of these manifestations and presents a unified view. When two galaxies merge, a binary black hole is formed and the two black holes will spiral inwards and merge, emitting long gravitational waves, which could be detected by the future LISA satellite.
Download or read book An Introduction to Active Galactic Nuclei written by Bradley M. Peterson and published by Cambridge University Press. This book was released on 1997-02-13 with total page 258 pages. Available in PDF, EPUB and Kindle. Book excerpt: How can we test if a supermassive black hole lies at the heart of every active galactic nucleus? What are LINERS, BL Lacs, N galaxies, broad-line radio galaxies and radio-quiet quasars and how do they compare? This timely textbook answers these questions in a clear, comprehensive and self-contained introduction to active galactic nuclei - for graduate students in astronomy and physics. The study of AGN is one of the most dynamic areas of contemporary astronomy, involving one fifth of all research astronomers. This textbook provides a systematic review of the observed properties of AGN across the entire electromagnetic spectrum, examines the underlying physics, and shows how the brightest AGN, quasars, can be used to probe the farthest reaches of the Universe. This book serves as both an entry point to the research literature and as a valuable reference for researchers in the field.
Download or read book Active Galactic Nuclei written by Volker Beckmann and published by John Wiley & Sons. This book was released on 2012-09-24 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 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 Scientific and Technical Aerospace Reports written by and published by . This book was released on 1994 with total page 364 pages. Available in PDF, EPUB and Kindle. Book excerpt:
