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Active Galactic Nuclei Studies In Cosmic X Ray Survey Fields
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Book Synopsis Active Galactic Nuclei Studies in Cosmic X-ray Survey Fields by : Qingling Ni
Download or read book Active Galactic Nuclei Studies in Cosmic X-ray Survey Fields written by Qingling Ni and published by . This book was released on 2021 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: X-ray surveys are an effective way to study growing supermassive black holes (SMBHs) in galaxy centers, as actively accreting SMBHs manifest themselves as active galactic nuclei (AGN) that can be observed in the X-ray in most cases. Through studying AGNs in X-ray survey fields that have extensive multiwavelength data coverage, we can probe how SMBH growth links with their host galaxies over cosmic history. Previously, researchers mainly linked SMBH growth with stellar mass (M⋆) or star formation rate (SFR). In this dissertation, we utilize morphological information to show that among star-forming (SF) galaxies, long-term average SMBH accretion rate (BHAR) relates to host-galaxy compactness (Chapter 2). We found that the relation between BHAR and host-galaxy compactness is more fundamental than the relation between BHAR and M⋆ or SFR (Chapter 3). This dissertation also provides key results from the XMM-Spitzer Extragalactic Representative Volume Survey (XMM-SERVS), which will benefit studies of SMBH growth in the next decade with a large sample of AGNs that have superb multiwavelength data. The detection of X-ray point sources in two of the XMM-SERVS survey fields is presented in Chapter 4. In Chapter 5, multiwavelength counterpart identification, photometric-redshift calculation, and source classification for X-ray sources in the XMM-SERVS survey fields are presented; most of the X-ray point-like sources detected are classified as AGNs, showing SMBH growth over the full range of cosmic environments. A Hyper Suprime-Cam (HSC) forced-photometry catalog that provides optical coverage for one of the XMM-SERVS survey fields is presented in Chapter 6. Apart from these works that focus on "Active Galactic Nuclei Studies in Cosmic X-ray Survey Fields", this dissertation also includes my other two first-author works in the appendices, where X-ray observational studies of weak-line quasars (WLQs) are presented. By studying these quasars with exceptional spectroscopic properties, we found good supporting evidence for optically thick inner accretion disks among quasars with high Eddington ratios.
Book Synopsis X-ray Studies of the Central Engine in Active Galactic Nuclei with Suzaku by : Hirofumi Noda
Download or read book X-ray Studies of the Central Engine in Active Galactic Nuclei with Suzaku written by Hirofumi Noda and published by Springer. This book was released on 2015-12-07 with total page 164 pages. Available in PDF, EPUB and Kindle. Book excerpt: The aim of this research was to use the X-ray satellite Suzaku to establish a picture of a central engine that effectively converts the gravitational energy of accreting matter onto the supermassive black hole to a huge amount of radiation in an active galactic nucleus. Although the engine is known to consist of a Comptonizing corona and an accretion disk, its image has remained unclear because primary emissions, coming directly from the engine, cannot be identified in X-ray spectra without models. The book describes a technique of time variability assisted spectral decomposition to model-independently examine X-ray signals, and how this was applied to the Suzaku archive data of active galactic nuclei. As a result, at least three distinct primary X-ray components have been discovered in an X-ray from an active galactic nucleus, presumably indicating a novel picture that the engine is composed of multiple coronae with different physical properties in an accretion flow. Furthermore, the determination of the spectral shapes of the primary X-rays has a significant impact on estimations of black hole spins, because it is essential to quantify reprocessed X-ray spectra. The successful model-independent decomposition of X-ray spectral components with flux variations of active galactic nuclei is likely to be effective in future data analyses from the soon-to-be-launched Japanese X-ray satellite ASTRO-H, which is capable of achieving unprecedented fine spectros copy and broad energy band coverage.
Book Synopsis X-ray and Multiwavelength Studies of Active Galactic Nuclei from Large Area Sky Surveys by : Jianfeng Wu
Download or read book X-ray and Multiwavelength Studies of Active Galactic Nuclei from Large Area Sky Surveys written by Jianfeng Wu and published by . This book was released on 2012 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Active galactic nuclei (AGNs) are ideal laboratories for fundamental physics and cosmology. Our knowledge of AGNs has been greatly advanced during the past decades thanks to the unprecedentedly powerful X-ray missions (e.g., Chandra, XMM-Newton, and Swift) and modern large area surveys in the optical/UV band (e.g., the Sloan Digital Sky Survey; SDSS). Studies on the relation between multiwavelength properties of AGNs can reveal the physics of AGN accretion process. In this dissertation, I mainly study the relation between the AGN X-ray properties and their optical/UV spectral properties on emission lines, absorption lines and continuum. I also investigate the X-ray properties of AGNs with extreme radio properties in the early Universe. (1) We studied the X-ray properties of a class of radio-quiet SDSS quasars with weak broad emission lines (weak-line quasars; WLQs). Although the WLQ population shows diverse X-ray properties, they have an excess of X-ray weak sources. Besides having weak emission lines, the X-ray weak WLQs generally show other unusual UV emission-line properties similar to those of the remarkable X-ray weak quasar PHL 1811 (e.g., highly blueshifted C IV lines, weak semi-forbidden lines, and strong UV Fe emission). They are classified as "PHL 1811 analogs". The X-ray weak WLQs also show a harder X-ray spectrum, while the WLQ with normal X-ray brightness have similar X-ray spectral properties to those of typical quasars. We proposed an AGN geometry which can potentially unify the X-ray weak and X-ray normal WLQ populations via orientation effect. The infrared-to-UV spectral energy distributions (SEDs) of X-ray weak and X-ray normal WLQs have consistent SEDs with those for typical quasars, which disfavors the BL Lac-like scenario for the nature of these quasars (Chapters 2 and 3). (2) We have led the best X-ray study to date on quasars with intermediate-width absorption lines (mini-BALs). We found the X-ray brightness of mini-BAL quasars are more close to those of typical quasars than to BAL quasars (which are generally X-ray weak), showing they do not have substantial X-ray absorption. Strong correlations were found between the X-ray brightness and UV absorption parameters, e.g., the absorption strength and maximum outflow velocity. We further proposed new UV absorption parameters which better correlate with the X-ray properties than existing parameters do (Chapter 4). (3) We studied the relation between the optical/UV luminosity and X-ray luminosity (quantified by the alpha_ox parameter) for the most-luminous quasars over a wide range of redshifts. Our correlation analyses provide better constraints on the alpha_ox-UV luminosity correlation. We have also verified that the alpha_ox parameter does not significantly evolve with redshift. We provide the individual and composite mid-infrared-to-UV SEDs for the most-luminous quasars. (Chapter 5). (4) We presented the X-ray and multiwavelength properties of the highly radio-loud quasars (HRLQs) at z > 4. Our HRLQs show a significant enhancement of X-ray emission over those HRLQs at lower redshift with similar optical/UV and radio luminosities, suggesting that the jet-linked X-ray emission mechanism in the early universe may differ from that in the more evolved universe. The optical/UV emission-line strength of RLQs are correlated with radio loudness, but not with relative X-ray brightness. Our HRLQs generally follow the anti-correlation between radio loudness and X-ray power-law photon index. We also studied the broad-band SEDs of HRLQs. Some HRLQs have an excess of mid-infrared emission which may originate from the jet synchrotron emission. None of our z > 4 HRLQs is detected by the Fermi LAT two-year survey (Chapter 6).
Book Synopsis Physics of Active Galactic Nuclei at All Scales by : Danielle Alloin
Download or read book Physics of Active Galactic Nuclei at All Scales written by Danielle Alloin and published by Lecture Notes in Physics. This book was released on 2006-07-24 with total page 258 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book contains a collection of lecture notes written by recognized experts in the field of Active Galactic Nuclei (AGN). The collection is aimed at providing both an introduction and at the same time an overview of the state-of-the-art of AGN research. This book also addresses the still not entirely understood link of an AGN with its host galaxy and also the related question of the birth and growth of massive black holes in the Universe.
Book Synopsis Active Galactic Nuclei by : Julian H. Krolik
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.
Book Synopsis High Energy Studies of Active Galactic Nuclei with XMM-Newton by : Rebecca Jane Smith
Download or read book High Energy Studies of Active Galactic Nuclei with XMM-Newton written by Rebecca Jane Smith and published by . This book was released on 2009 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Book Synopsis The X-ray Background by : Xavier Barcons
Download or read book The X-ray Background written by Xavier Barcons and published by Cambridge University Press. This book was released on 1992-07-31 with total page 328 pages. Available in PDF, EPUB and Kindle. Book excerpt: A review of the current observational knowledge and understanding of the cosmic X-ray background.
Book Synopsis Physics of Active Galactic Nuclei at all Scales by : Danielle Alloin
Download or read book Physics of Active Galactic Nuclei at all Scales written by Danielle Alloin and published by Springer. This book was released on 2009-09-02 with total page 234 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book contains a collection of lecture notes written by recognized experts in the field of Active Galactic Nuclei (AGN). The collection is aimed at providing both an introduction and at the same time an overview of the state-of-the-art of AGN research. This book also addresses the still not entirely understood link of an AGN with its host galaxy and also the related question of the birth and growth of massive black holes in the Universe.
Book Synopsis Cosmological Evolution of X-ray Emitting Active Galactic Nuclei by : John David Silverman
Download or read book Cosmological Evolution of X-ray Emitting Active Galactic Nuclei written by John David Silverman and published by . This book was released on 2004 with total page 396 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Book Synopsis Currents in Astrophysics and Cosmology by : G. G. Fazio
Download or read book Currents in Astrophysics and Cosmology written by G. G. Fazio and published by Cambridge University Press. This book was released on 1993-10-28 with total page 326 pages. Available in PDF, EPUB and Kindle. Book excerpt: Currents in Astrophysics and Cosmology focuses primarily on cosmic-ray physics, X-ray, gamma-ray and neutrino astronomy and cosmology, the main research areas of Professor Maurice M. Shapiro, whose 75th birthday the collection of articles celebrates. Professor Shapiro is internationally distinguished for his contributions to the development of cosmic-ray physics. Each chapter is written by a leading scientist in the field. The scope extends from the inner solar system to distant radio galaxies. The book is ideal for graduate students and scientists working in cosmic-ray astrophysics. This valuable survey will be welcomed not only for its articles by world-renowned scientists but also for its coverage of many topics in high-energy astrophysics, the combination of which makes the book unique.
Book Synopsis An Introduction to Active Galactic Nuclei by : Bradley M. Peterson
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.
Book Synopsis Astronomy and Astrophysics for the 1980's, Volume 2 by : National Research Council
Download or read book Astronomy and Astrophysics for the 1980's, Volume 2 written by National Research Council and published by National Academies Press. This book was released on 1983-02-01 with total page 464 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Book Synopsis X-ray Surveys of Active Galactic Nuclei in Field and Cluster Environments by : Catharine Olivia Carver Johnson
Download or read book X-ray Surveys of Active Galactic Nuclei in Field and Cluster Environments written by Catharine Olivia Carver Johnson and published by . This book was released on 2004 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Book Synopsis X-ray and Multiwavelength Studies of Active Galactic Nuclei in the Chandra Deep Fields by : Bin Luo
Download or read book X-ray and Multiwavelength Studies of Active Galactic Nuclei in the Chandra Deep Fields written by Bin Luo and published by . This book was released on 2010 with total page 175 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Book Synopsis Frontiers of X-Ray Astronomy by : A. C. Fabian
Download or read book Frontiers of X-Ray Astronomy written by A. C. Fabian and published by Cambridge University Press. This book was released on 2004-07-08 with total page 260 pages. Available in PDF, EPUB and Kindle. Book excerpt: X-ray astronomy has undergone a revolution in recent years. With the launch of two orbiting observatories, Chandra and XMM-Newton, astronomers are now able to obtain spectra and images at a higher resolution than ever before. Observations have had a major impact on topics ranging from protostars to cosmology. The contributions in this 2004 work, by leading authorities in the field, originate from a Royal Society Discussion Meeting that was held to review results from the current generation of X-ray telescopes, and set them in context. This book is a valuable reference for research astronomers and graduate students wishing to understand the latest developments in this exciting field.
Book Synopsis X-ray Surveys of Active Galactic Nuclei in Field and Cluster Environments by : Catharine Olivia Carver Johnson
Download or read book X-ray Surveys of Active Galactic Nuclei in Field and Cluster Environments written by Catharine Olivia Carver Johnson and published by . This book was released on 2005 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Book Synopsis Working Papers by : Astronomy and Astrophysics Survey Committee
Download or read book Working Papers written by Astronomy and Astrophysics Survey Committee and published by . This book was released on 1991-01-15 with total page 362 pages. Available in PDF, EPUB and Kindle. Book excerpt: This volume contains working papers on astronomy and astrophysics prepared by 15 non-National Research Council panels in areas ranging from radio astronomy to the status of the profession.
