The Cosmic Evolution Of Galaxy Structure

Galaxies are the fundamental units of cosmic matter that make up the universe and they change in remarkable ways over 13.7 billion years of cosmic time. We are just now discovering how galaxies we can see over these billions of years are evolving from small, star forming systems to larger, more massive and passive systems at later times. This book explains the structural evolution of galaxies, how we measure it, how these measurements change with time, and how observing this reveals important information about galaxy formation and evolution. It also explains the future of the field through the use of machine learning tools, and how galaxy structure can be used as a new approach to measure unique features of the universe, such as cosmological properties and parameters.

An Astronomical Life – Observing the Depths of the Universe” Though science as a subject can be di?cult, what has been more important for me is that its practice can also be rewarding fun! This book is crafted to expose the reader to the excitement of modern observational cosmology through the study of galaxy evolution over space and cosmic time. Recent extragalactic research has led to many rapid advances in the ?eld. Even a suitable skeptic of certain pronouncements about the age and structure of the Universe should be pleased with the large steps that have been taken in furthering our understanding of the Universe since the early 1990’s. My personal involvement in galaxy research goes back to the 1960’s. At that point, galaxies were easily recognized and partially understood as organized c- lections of stars and gas. What their masses were presented a problem, which I supposed would just fade away. But fade it didn’t. Distant active nuclei and quasars were discovered in the mid-1960’s. A c- mon view of QSOs was that they have large redshifts, but what use are they for cosmology or normal galaxy astrophysics? I shared that conclusion. My expec- tions fell below their potential utility. In short, the Universe of our expectations rarely matches the Universe as it is discovered.

Galaxies are large systems of stars, some of which contain interstellar gas and dust. They also contain much invisible matter, which may be in the form of weakly interacting elementary particles. In this introductory textbook, the first chapter introduces the study of galaxies. This is followed by two chapters on observations of galaxies, including our own. There are then three chapters on galactic structure: the manner in which motions of stars determine galactic shape, the determination of galactic masses, and the structure of discs in spirals. Galactic evolution, especially changes in chemical composition over time, is covered. The book concludes with a discussion of the origin of galaxies and their relation to more general questions in cosmology. The book includes mathematical presentation where this enables the discussion to be quantitative.

Delineating the huge strides taken in cosmology in the past ten years, this much-anticipated second edition of Malcolm Longair's highly appreciated textbook has been extensively and thoroughly updated. It tells the story of modern astrophysical cosmology from the perspective of one of its most important and fundamental problems – how did the galaxies come about? Longair uses this approach to introduce the whole of what may be called "classical cosmology". What’s more, he describes how the study of the origin of galaxies and larger-scale structures in the Universe has provided us with direct information about the physics of the very early Universe.

The rapidly expanding field of galaxy formation lies at the interface between astronomy, particle physics, and cosmology. Covering diverse topics from these disciplines, all of which are needed to understand how galaxies form and evolve, this book is ideal for researchers entering the field. Individual chapters explore the evolution of the Universe as a whole and its particle and radiation content; linear and nonlinear growth of cosmic structure; processes affecting the gaseous and dark matter components of galaxies and their stellar populations; the formation of spiral and elliptical galaxies; central supermassive black holes and the activity associated with them; galaxy interactions; and the intergalactic medium. Emphasizing both observational and theoretical aspects, this book provides a coherent introduction for astronomers, cosmologists, and astroparticle physicists to the broad range of science underlying the formation and evolution of galaxies.

Awarded the American Astronomical Society (AAS) Rodger Doxsey Travel Prize, and with a foreword by thesis supervisor Professor Shardha Jogee at the University of Texas at Austin, this thesis discusses one of the primary outstanding problems in extragalactic astronomy: how galaxies form and evolve. Galaxies consist of two fundamental kinds of structure: rotationally supported disks and spheroidal/triaxial structures supported by random stellar motions. Understanding the balance between these galaxy components is vital to comprehending the relative importance of the different mechanisms (galaxy collisions, gas accretion and internal secular processes) that assemble and shape galaxies. Using panchromatic imaging from some of the largest and deepest space-based galaxy surveys, an empirical census of galaxy structure is made for galaxies at different cosmic epochs and in environments spanning low to extremely high galaxy number densities. An important result of this work is that disk structures are far more prevalent in massive galaxies than previously thought. The associated challenges raised for contemporary theoretical models of galaxy formation are discussed. The method of galaxy structural decomposition is treated thoroughly since it is relevant for future studies of galaxy structure using next-generation facilities, like the James Webb Space Telescope and the ground-based Giant Magellan Telescope with adaptive optics.