Galaxies are vast ensembles of stars, gas and dust, embedded in dark matter halos. They are the basic building blocks of the Universe, gathered in groups, clusters and super-clusters. They exist in many forms, either as spheroids or disks. Classifications, such as the Hubble sequence (based on mass concentration and gas fraction) and the colormagnitude diagram (which separates a blue cloud from a red sequence) help to understand their formation and evolution. Galaxies spend a large part of their lives in the blue cloud, forming stars as spiral or dwarf galaxies. Then, via a mechanism that is still unclear, they stop forming stars and quietly end in the red sequence, as spheroids. This transformation may be due to galaxy interactions, or because of the feedback of active nuclei, through the energy released by their central super-massive black holes. These mechanisms could explain the history of cosmic star formation, the rate of which was far greater in the first half of the UniverseÂs life. Galaxies delves into all of these surrounding subjects in six chapters written by dedicated, specialist astronomers and researchers in the field, from their numerical simulations to their evolutions.
The Origin and Evolution of Galaxies is the outstanding problem of modern cosmology. Fortunately. we have a firm cosmological framework on which to base our theories (the hot big bang) and recently there has been substantial progress in providing observations which potentially can constrain these theories. The problem of galaxy formation is. as a consequence. one involving many diverse branches of physics and astrophysics. It has been the aim of the school. and this compendium of lectures and seminars. to bring together these diverse aspects at a level enabling research workers to understand what is going on in other corners of the subject and to see how progress in each area impinges on the others. We are grateful to the contributors to this volume for allowing us considerable editorial license with their articles. We have attempted to provide a representative sample of the talks that were given at the school besides the texts of the invited lecturers. It is regrettable that for reasons of space we have had to leave out a number of other contributions.
The Structure and Evolution of Galaxies is a concise introduction to this fascinating subject providing the reader with the fundamentals in a clear and accessible style. This user-friendly text assumes some prerequisite knowledge of astronomy, with the necessary mathematics kept to a minimum. Beginning with an introduction to the existence of our own external galaxies, the book moves on to discuss how perceptions of galaxy development have changed over time. The three categories of galaxies are then discussed with later chapters considering their formation and evolution. The book concludes with an overview of both current developments in the field and considers the direction of future research. Clear and accessible introduction to this dynamic subject Introduces definitions of key terms and puts them in context Includes current research and future developments in the field Appendix of basic definitions to clarify key concepts An invaluable text for students of astronomy and physics
This edition of Science and Creationism summarizes key aspects of several of the most important lines of evidence supporting evolution. It describes some of the positions taken by advocates of creation science and presents an analysis of these claims. This document lays out for a broader audience the case against presenting religious concepts in science classes. The document covers the origin of the universe, Earth, and life; evidence supporting biological evolution; and human evolution. (Contains 31 references.) (CCM)
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.
The term “chemical evolution of galaxies” refers to the evolution of abundances of chemical species in galaxies, which is due to nuclear processes occurring in stars and to gas flows into and out of galaxies. This book deals with the chemical evolution of galaxies of all morphological types (ellipticals, spirals and irregulars) and stresses the importance of the star formation histories in determining the properties of stellar populations in different galaxies. The topic is approached in a didactical and logical manner via galaxy evolution models which are compared with observational results obtained in the last two decades: The reader is given an introduction to the concept of chemical abundances and learns about the main stellar populations in our Galaxy as well as about the classification of galaxy types and their main observables. In the core of the book, the construction and solution of chemical evolution models are discussed in detail, followed by descriptions and interpretations of observations of the chemical evolution of the Milky Way, spheroidal galaxies, irregular galaxies and of cosmic chemical evolution. The aim of this book is to provide an introduction to students as well as to amend our present ideas in research; the book also summarizes the efforts made by authors in the past several years in order to further future research in the field.
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.
'This book presents a clear, highly readable view of science's best understanding of how things in the Universe came to be the way they are. Each chapter is written by a leading expert in that sub-field. Together they cover nearly all major advances made in the past century, in fields from cosmology to exobiology.'Joseph H Taylor Jr.Nobel Laureate in Physics, 1993'An exhilarating tour of the Universe from true experts. For those who thirst to know how we know what we know about our place in the Universe, reading this book will be a richly rewarding experience.'Adam G RiessNobel Laureate in Physics, 2011'These are fascinating essays about the nature of the world around us by people who write well and understand what they are writing about.'P James E PeeblesNobel Laureate in Physics, 2019The book provides a broad overview of what we currently know about the Origin and Evolution of the Universe. The goal is to be scientifically comprehensive but concise. We trace the origins from the Big Bang and cosmic expansion, to the formation of galaxies, heavy elements, stars and planets as abodes for life. This field has made stunning progress since the first edition of this book. At that time, there were no known planets outside of our own Solar System (compared with the many thousands currently being studied). The origin of massive black holes was pure speculation (compared with the very recent detection of the first gravitational waves from space, produced by the cataclysmic merger of two surprisingly large black holes). And the most important energy in the Universe, now known as the Dark Energy which is accelerating the expansion, had not been discovered. We aim to bring lay readers with an interest in science 'up to speed' on all of these key discoveries that are part of the panorama of cosmic evolution, which has ultimately lead to our existence on Earth.Related Link(s)