Download or read book Logarithmic Spiral Arm Pitch Angle of Spiral Galaxies written by Benjamin Lee Davis and published by . This book was released on 2015 with total page 336 pages. Available in PDF, EPUB and Kindle. Book excerpt: In this dissertation, I explore the geometric structure of spiral galaxies and how the visible structure can provide information about the central mass of a galaxy, the density of its galactic disk, and the hidden mass of the supermassive black hole in its nucleus. In order to quantitatively measure the logarithmic spiral pitch angle (a measurement of tightness of the winding) of galactic spiral arms, I led an effort in our research group (the Arkansas Galaxy Evolution Survey) to modify existing two-dimensional fast Fourier transform software to increase its efficacy and accuracy. Using this software, I was able to lead an effort to calculate a black hole mass function (BHMF) for spiral galaxies in our local Universe. This work effectively provides us with a census of local black holes and establishes an endpoint on the evolutionary history of the BHMF for spiral galaxies. Furthermore, my work has indicated a novel fundamental relationship between the pitch angle of a galaxy's spiral arms, the maximum density of neutral atomic hydrogen in its disk, and the stellar mass of its bulge. This result provides strong support for the density wave theory of spiral structure in disk galaxies and poses a critical question of the validity of rival theories for the genesis of spiral structure in disk galaxies.
Download or read book The Disk Structure of Late Type Galaxies written by Michael S. Fusco and published by . This book was released on 2019 with total page 292 pages. Available in PDF, EPUB and Kindle. Book excerpt: This dissertation pertains to the geometric structure of late type (spiral) galaxies, specifically on the relation between the logarithmic spiral pitch angle of the galactic spiral arms with other properties of the galaxy, such as central Supermassive Black Hole (SMBH) mass. Our work continues a study of the Black Hole Mass Function (BHMF) in local galaxies by recording the pitch angles of spiral galaxies with lower surface brightness than were previously included. We also conduct a case study on the structure of an interestingly shaped galaxy, UGC 4599. Previous studies on the topic of spiral arm pitch angles have measured the pitch angle of galaxies using a variety of image analysis techniques. Here the effectiveness of two of these techniques are assessed under different galaxy conditions and their errors and failure modes are probed as the measurement characteristics of simulated galaxies are manipulated and degraded. This is done for the purpose of recognizing and accounting for the limits of techniques for measuring the pitch angles of galaxies as they increase in redshift or decrease in surface brightness or angular resolution (pixel size). As a result, imaging based relations in galaxy structure may be applied to extend measurements from the local universe to greater distances as long as image degradation with distance is accounted for. In exploring populations of galaxies, errors in distribution studies might result from gaps in selection; galaxies with too little apparent structure or too faint a surface brightness to be recognized as spirals and included in the study. Errors might also result from inaccuracy or failure on the measurement side, where low resolution, low surface brightness galaxies produce pitch angle measurements characterized by higher failure rates and higher associated errors for successful measurements. We work to employ new techniques to minimize these errors as well as understand and account for their effects on the distributions being measured.
Download or read book Galactic Dynamics written by James Binney and published by Princeton University Press. This book was released on 2011-10-30 with total page 902 pages. Available in PDF, EPUB and Kindle. Book excerpt: Since it was first published in 1987, Galactic Dynamics has become the most widely used advanced textbook on the structure and dynamics of galaxies and one of the most cited references in astrophysics. Now, in this extensively revised and updated edition, James Binney and Scott Tremaine describe the dramatic recent advances in this subject, making Galactic Dynamics the most authoritative introduction to galactic astrophysics available to advanced undergraduate students, graduate students, and researchers. Every part of the book has been thoroughly overhauled, and many sections have been completely rewritten. Many new topics are covered, including N-body simulation methods, black holes in stellar systems, linear stability and response theory, and galaxy formation in the cosmological context. Binney and Tremaine, two of the world's leading astrophysicists, use the tools of theoretical physics to describe how galaxies and other stellar systems work, succinctly and lucidly explaining theoretical principles and their applications to observational phenomena. They provide readers with an understanding of stellar dynamics at the level needed to reach the frontiers of the subject. This new edition of the classic text is the definitive introduction to the field. ? A complete revision and update of one of the most cited references in astrophysics Provides a comprehensive description of the dynamical structure and evolution of galaxies and other stellar systems Serves as both a graduate textbook and a resource for researchers Includes 20 color illustrations, 205 figures, and more than 200 problems Covers the gravitational N-body problem, hierarchical galaxy formation, galaxy mergers, dark matter, spiral structure, numerical simulations, orbits and chaos, equilibrium and stability of stellar systems, evolution of binary stars and star clusters, and much more Companion volume to Galactic Astronomy, the definitive book on the phenomenology of galaxies and star clusters
Download or read book Setting the Scene for Gaia and LAMOST IAU S298 written by Sofia Feltzing and published by Cambridge University Press. This book was released on 2014-01-30 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Gaia is an ambitious satellite mission to chart a three-dimensional map of the Milky Way. By measuring the proper motions and parallaxes for a billion stars, Gaia is set to transform the way we study the composition, formation and evolution of our galaxy. Concurrently the LAMOST survey facility in China will make a complementary spectral survey of millions of objects in much of the northern sky. This volume, comprising the reviews and contributed talks presented at IAU Symposium 298, is an up-to-date review of what we know about the Milky Way as a galaxy prior to the launch of Gaia. It covers many topics including the status of dynamical simulations, photometric and spectroscopic surveys, and interstellar matter in the Milky Way, as well as detailed studies of stellar atmospheres. The expert reviews will interest all those working on Milky Way astronomy as well as galaxy formation and evolution.
Download or read book Spiral Structure in Galaxies written by Marc S Seigar and published by Morgan & Claypool Publishers. This book was released on 2017-06-29 with total page 84 pages. Available in PDF, EPUB and Kindle. Book excerpt: How does it happen that billions of stars can cooperate to produce the beautiful spirals that characterize so many galaxies, including ours? This book reviews the history behind the discovery of spiral galaxies and the problems faced when trying to explain the existence of spiral structure within them. In the book, subjects such as galaxy morphology and structure are addressed as well as several models for spiral structure. The evidence in favor or against these models is discussed. The book ends by discussing how spiral structure can be used as a proxy for other properties of spiral galaxies, such as their dark matter content and their central supermassive black hole masses, and why this is important.
Download or read book Atlas of Galaxies written by Ronald J. Buta and published by Cambridge University Press. This book was released on 2007-03-08 with total page 13 pages. Available in PDF, EPUB and Kindle. Book excerpt: New illustrated atlas on modern galaxy classification for astronomy researchers, students, and amateurs.
Download or read book An Upper Limit on the Tightening of Galactic Spiral Arm Pitch Angle in Cosmic Time written by Douglas William Shields and published by . This book was released on 2017 with total page 226 pages. Available in PDF, EPUB and Kindle. Book excerpt: We present Spirality, a novel method of measuring pitch angle by fitting galaxy images to spiral templates of known pitch. Using this algorithm in concert with 2-dimensional Fast Fourier Transform (2DFFT), we determined that the pitch angle of the redshift 2.011 galaxy GZ5001 (J2000 RA 189.14811 degrees, Dec 62.24002 degrees) is approximately (16.2 +/- 2.6) degrees. The redshift 2.3219 galaxy GS21 (J2000 RA 53.14863 degrees, Dec -27.95469 degrees), which is believed to be the most distant galaxy with visible spiral structure yet measured, has a pitch of approximately (-10.6 +/- 1.6) degrees. Using a large sample of galaxies from the Great Observatories Origins Deep Survey (GOODS), we place an upper limit on the tightening of average spiral arm pitch angle with cosmic time. With 68% confidence, we find that the average pitch for such galaxies has decreased (tightened) by no more than 9.94 degrees per unit redshift. If we constrain our data to be consistent with the local pitch angle mass function, we find a result that is consistent with a constant average pitch angle over cosmic time.
Download or read book Cosmic Pinwheels Spiral Galaxies And The Universe written by Ronald J Buta and published by World Scientific. This book was released on 2020-10-29 with total page 486 pages. Available in PDF, EPUB and Kindle. Book excerpt: 'It is strongly biased towards the author's speciality of galaxy morphology, and particularly to bars and rings. To be fair, these are often given fairly short shrift in other textbooks, so this is a useful source of detail on such topics from an expert. In addition, references to original technical papers are given throughout which makes the book a handy introduction to the literature (which students may well find useful).'The Observatory MagazineThe main goal of the book is to introduce the reader to the world of spiral galaxies, how spirals were discovered, what they represent from a physical point of view, and what people have learned about the universe and the nature of galaxies in general from the study of spirals. Topics include early discoveries of nebulae, the island universe concept, the structure of spirals as seen both visually with telescopes and in images obtained with different filters, the role of spirals in the discovery of interstellar dust and dark matter, the different kinds of spiral galaxies and the importance of bars and rings, how different non-spiral galaxy types such as elliptical galaxies and S0 galaxies connect to spirals, and how spirals have contributed to our understanding of star formation and evolution, galaxy formation and evolution, the cosmological distance scale, and the universal expansion. The Milky Way as a spiral galaxy is also discussed.The book is profusely illustrated and not only a discourse on the spirals, but is also a personal reminiscence based on the author's studies of spiral galaxies over the past 45 years.
Download or read book Fundamentals of Galaxy Dynamics Formation and Evolution written by Ignacio Ferreras and published by UCL Press. This book was released on 2019-04-02 with total page 200 pages. Available in PDF, EPUB and Kindle. Book excerpt: Galaxies, along with their underlying dark matter halos, constitute the building blocks of structure in the Universe. Of all fundamental forces, gravity is the dominant one that drives the evolution of structures from small density seeds at early times to the galaxies we see today. The interactions among myriads of stars, or dark matter particles, in a gravitating structure produce a system with fascinating connotations to thermodynamics, with some analogies and some fundamental differences. Ignacio Ferreras presents a concise introduction to extragalactic astrophysics, with emphasis on stellar dynamics, and the growth of density fluctuations in an expanding Universe. Additional chapters are devoted to smaller systems (stellar clusters) and larger ones (galaxy clusters). Fundamentals of Galaxy Dynamics, Formation and Evolution is written for advanced undergraduates and beginning postgraduate students, providing a useful tool to get up to speed in a starting research career. Some of the derivations for the most important results are presented in detail to enable students appreciate the beauty of maths as a tool to understand the workings of galaxies. Each chapter includes a set of problems to help the student advance with the material.
Download or read book Galactic Astronomy written by James Binney and published by Princeton University Press. This book was released on 2021-07-13 with total page 818 pages. Available in PDF, EPUB and Kindle. Book excerpt: This is the definitive treatment of the phenomenology of galaxies--a clear and comprehensive volume that takes full account of the extraordinary recent advances in the field. The book supersedes the classic text Galactic Astronomy that James Binney wrote with Dimitri Mihalas, and complements Galactic Dynamics by Binney and Scott Tremaine. It will be invaluable to researchers and is accessible to any student who has a background in undergraduate physics. The book draws on observations both of our own galaxy, the Milky Way, and of external galaxies. The two sources are complementary, since the former tends to be highly detailed but difficult to interpret, while the latter is typically poorer in quality but conceptually simpler to understand. Binney and Merrifield introduce all astronomical concepts necessary to understand the properties of galaxies, including coordinate systems, magnitudes and colors, the phenomenology of stars, the theory of stellar and chemical evolution, and the measurement of astronomical distances. The book's core covers the phenomenology of external galaxies, star clusters in the Milky Way, the interstellar media of external galaxies, gas in the Milky Way, the structure and kinematics of the stellar components of the Milky Way, and the kinematics of external galaxies. Throughout, the book emphasizes the observational basis for current understanding of galactic astronomy, with references to the original literature. Offering both new information and a comprehensive view of its subject, it will be an indispensable source for professionals, as well as for graduate students and advanced undergraduates.
Download or read book The Spiral Structure of Our Galaxy written by Wilhelm Becker and published by . This book was released on 1970 with total page 500 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Spiral Structure in Galaxies written by Marc S Seigar and published by Morgan & Claypool Publishers. This book was released on 2017-06-29 with total page 84 pages. Available in PDF, EPUB and Kindle. Book excerpt: How does it happen that billions of stars can cooperate to produce the beautiful spirals that characterize so many galaxies, including ours? This book reviews the history behind the discovery of spiral galaxies and the problems faced when trying to explain the existence of spiral structure within them. In the book, subjects such as galaxy morphology and structure are addressed as well as several models for spiral structure. The evidence in favor or against these models is discussed. The book ends by discussing how spiral structure can be used as a proxy for other properties of spiral galaxies, such as their dark matter content and their central supermassive black hole masses, and why this is important.
Download or read book Spiral Structure in Galaxies written by Marc S Seigar and published by Morgan & Claypool Publishers. This book was released on 2017-06-29 with total page 112 pages. Available in PDF, EPUB and Kindle. Book excerpt: How does it happen that billions of stars can cooperate to produce the beautiful spirals that characterize so many galaxies, including ours? This book reviews the history behind the discovery of spiral galaxies and the problems faced when trying to explain the existence of spiral structure within them. In the book, subjects such as galaxy morphology and structure are addressed as well as several models for spiral structure. The evidence in favor or against these models is discussed. The book ends by discussing how spiral structure can be used as a proxy for other properties of spiral galaxies, such as their dark matter content and their central supermassive black hole masses, and why this is important.
Download or read book Spiral Structure in Galaxies written by Giuseppe Bertin and published by MIT Press. This book was released on 1996 with total page 296 pages. Available in PDF, EPUB and Kindle. Book excerpt: How does it happen that billions of stars can cooperate to produce the beautiful spirals that characterize so many galaxies, including ours? This book presents a theory of spiral structure that has been developed over the past three decades under the continuous stimulus of new observational studies. The theory unfolds in a way that can be grasped by any reader with an undergraduate science background who is interested in astronomy, as well as by graduate students and scientists actively involved in astronomy or related subjects who want to see the "backbone" and the physical content of the theory. The foundations of this theoretical framework were laid in the early 1960s, following the pioneering work of B. Lindblad. C. C. Lin had already contributed significantly to the field of fluid mechanics when he turned his attention to spiral structures, and he has focused on the problem ever since. Giuseppe Bertin joined this research effort when he first visited at MIT in 1975, bringing to the project knowledge from his work on elliptical galaxies and plasma astrophysics. Together, Bertin and Lin have contributed to the exciting developments on spiral structure of the last few decades, working closely with many observers and other theorists. In this book they describe the density-wave theory with the goal of making the key concepts and astrophysical implications explicit and accessible. The essence of the solution Bertin and Lin present is that the spirals are wave rather than material phenomena and generally trace intrinsic characteristics of the individual galaxies. The book is in three parts--Physical Concepts, Observational Studies, and Dynamical Mechanisms--with most of the technical details confined to the last part.
Download or read book Galaxies in the Universe written by Linda S. Sparke and published by Cambridge University Press. This book was released on 2007-02-05 with total page 442 pages. Available in PDF, EPUB and Kindle. Book excerpt: This extensively illustrated book presents the astrophysics of galaxies since their beginnings in the early Universe. It has been thoroughly revised to take into account the most recent observational data, and recent discoveries such as dark energy. There are new sections on galaxy clusters, gamma ray bursts and supermassive black holes. The authors explore the basic properties of stars and the Milky Way before working out towards nearby galaxies and the distant Universe. They discuss the structures of galaxies and how galaxies have developed, and relate this to the evolution of the Universe. The book also examines ways of observing galaxies across the whole electromagnetic spectrum, and explores dark matter and its gravitational pull on matter and light. This book is self-contained and includes several homework problems with hints. It is ideal for advanced undergraduate students in astronomy and astrophysics.
Download or read book Astrophysical Disks written by S. F. Dermott and published by . This book was released on 1992 with total page 360 pages. Available in PDF, EPUB and Kindle. Book excerpt: A companion to earlier volumes (497, 536, 596, 617 and 631) of the Annals, this entry in the nonlinear astronomy series has contributions by most of the acknowledged experts in the field. They write on many topics, all of current interest. As several hold strong opposing views, this is a lively, important and timely publication.
Download or read book Dynamics of Galaxies written by Giuseppe Bertin and published by Cambridge University Press. This book was released on 2014-04-21 with total page 487 pages. Available in PDF, EPUB and Kindle. Book excerpt: Provides advanced students with an introduction to modern galactic dynamics, and equips them with useful observational and theoretical tools.
