Photoionization Modelling as a Density Diagnostic of Line Emitting/Absorbing Regions in Active Galactic Nuclei
Photoionization Modelling as a Density Diagnostic of Line Emitting/Absorbing Regions in Active Galactic Nuclei

Author: Tek Prasad Adhikari

Publisher: Springer

Published: 2019-06-29

Total Pages: 139

ISBN-13: 3030227375

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This book presents timely work on the nature of the physical processes underpinning two of the basic characteristics of the gas structure in the innermost region of Active Galactic Nuclei (AGN): ionized outflows and emission line regions. In addition, it describes physics-based methods for estimating the density of the astrophysical plasma surrounding AGN. All numerical computations of the photoionized gas employ the most advanced codes available (CLOUDY and TITAN). Calculations of the radiative transfer are based on the assumption of thermal and ionization equilibrium. Promising preliminary examples of comparison with current observations are included for several individual AGN. All of them suggest that the absorbing/emitting gas should have a density on the order of 1012 cm-3. Future observations will provide more objects to verify these results, and will allow us to put constraints on the launch radius of ionized outflows and therefore on the mass loading and kinetic energy outflow rates. These rates, in turn, are crucial to estimating whether the outflows have a significant feedback impact on star formation and metal enrichment in the interstellar medium of the host galaxy. In closing, the book discusses a representative example of applying powerful photoionization techniques to explain the complex physics of the AGN environment.

Astrophysics Of Gas Nebulae and Active Galactic Nuclei
Astrophysics Of Gas Nebulae and Active Galactic Nuclei

Author: Donald E. Osterbrock

Publisher: University Science Books

Published: 2006

Total Pages: 488

ISBN-13: 9781891389344

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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.

Astrophysics of the Diffuse Universe
Astrophysics of the Diffuse Universe

Author: Michael A. Dopita

Publisher: Springer Science & Business Media

Published: 2013-06-29

Total Pages: 445

ISBN-13: 3662058669

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The reference work on astrophysics to provide a comprehensive introduction to the physics of Interstellar Matter. The objective of the book is to show how physics can be applied to the understanding and diagnosis of the phase structure, the physical conditions and the chemical make-up and evolution of the interstellar medium. Unlike other textbooks in the field, here a more systematic approach has been adopted based on the authors' lecture course experience. It is aimed primarily at those undertaking post-graduate courses, or those doing advanced projects as part of honours undergraduate courses in physics or astrophysics.

An Introduction to Active Galactic Nuclei
An Introduction to Active Galactic Nuclei

Author: Bradley M. Peterson

Publisher: Cambridge University Press

Published: 1997-02-13

Total Pages: 258

ISBN-13: 9780521479110

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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.

Active Galactic Nuclei
Active Galactic Nuclei

Author: Julian H. Krolik

Publisher: Princeton University Press

Published: 2021-03-09

Total Pages: 632

ISBN-13: 0691227470

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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.

Eta Carinae and the Supernova Impostors
Eta Carinae and the Supernova Impostors

Author: Kris Davidson

Publisher: Springer Science & Business Media

Published: 2012-03-15

Total Pages: 334

ISBN-13: 1461422752

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In 1965 Fritz Zwicky proposed a class of supernovae that he called "Type V", described as "excessively faint at maximum". There were only two members, SN1961v and Eta Carinae. We now know that Eta Carinae was not a true supernova, but if it were observed today in a distant galaxy we would call it a "supernova impostor". 170 years ago it experienced a "great eruption" lasting 20 years, expelling 10 solar masses or more, and survived. Eta Carinae is now acknowledged as the most massive, most luminous star in our region of the Galaxy, and it may be our only example of a very massive star in a pre-supernova state. In this book the editors and contributing authors review its remarkable history, physical state of the star and its ejecta, and its continuing instability. Chapters also include its relation to other massive, unstable stars, the massive star progenitors of supernovae, and the "first" stars in the Universe.