The Extragalactic Distance Scale


Book Description

One of the hottest debates in astronomy and cosmology today concerns the value of the Hubble constant. This constant is of paramount importance since it fixes the size and age of the Universe. At a symposium at the Space Telescope Science Institute, experts from around the world presented the latest results from a plethora of techniques for determining the Hubble constant. The value has always been controversial, but at this meeting experts' results agreed for the first time to within about 20%. Based on the meeting, this book presents twenty-three specially written review articles. They provide a comprehensive account of the Hubble-constant debate with the latest results from gravitational lensing, supernovae and novae, the Tully-Fisher relation, the Sunyaev-Zeldovich effect, globular clusters, planetary nebulae, light echoes, and the Hubble Space Telescope Key Project. This timely volume provides a standard reference for graduate students and researchers in astronomy and cosmology.




Introduction to Gravitational Lensing


Book Description

This book introduces the phenomenology of gravitational lensing in an accessible manner and provides a thorough discussion of the related astrophysical applications. It is intended for advanced undergraduates and graduate students who want to start working in this rapidly evolving field. This includes also senior researchers who are interested in ongoing or future surveys and missions such as DES, Euclid, WFIRST, LSST. The reader is guided through many fascinating topics related to gravitational lensing like the structure of our galaxy, the searching for exoplanets, the investigation of dark matter in galaxies and galaxy clusters, and several aspects of cosmology, including dark energy and the cosmic microwave background. The author, who has gained valuable experience as academic teacher, guides the readers towards the comprehension of the theory of gravitational lensing and related observational techniques by using simple codes written in python. This approach, beyond facilitating the understanding of gravitational lensing, is preparatory for learning the python programming language which is gaining large popularity both in academia and in the private sector.




Gravitational Lensing: Strong, Weak and Micro


Book Description

The observation, in 1919 by A.S. Eddington and collaborators, of the gra- tational de?ection of light by the Sun proved one of the many predictions of Einstein’s Theory of General Relativity: The Sun was the ?rst example of a gravitational lens. In 1936, Albert Einstein published an article in which he suggested - ing stars as gravitational lenses. A year later, Fritz Zwicky pointed out that galaxies would act as lenses much more likely than stars, and also gave a list of possible applications, as a means to determine the dark matter content of galaxies and clusters of galaxies. It was only in 1979 that the ?rst example of an extragalactic gravitational lens was provided by the observation of the distant quasar QSO 0957+0561, by D. Walsh, R.F. Carswell, and R.J. Weymann. A few years later, the ?rst lens showing images in the form of arcs was detected. The theory, observations, and applications of gravitational lensing cons- tute one of the most rapidly growing branches of astrophysics. The gravi- tional de?ection of light generated by mass concentrations along a light path producesmagni?cation,multiplicity,anddistortionofimages,anddelaysp- ton propagation from one line of sight relative to another. The huge amount of scienti?c work produced over the last decade on gravitational lensing has clearly revealed its already substantial and wide impact, and its potential for future astrophysical applications.




Astrophysical Applications of Gravitational Lensing


Book Description

This book presents gravitational lensing as an essential tool in astrophysics for tracking dark matter at all scales in the Universe.




Your Place in the Universe


Book Description

An astrophysicist presents an in-depth yet accessible tour of the universe for lay readers, while conveying the excitement of astronomy.How is a galaxy billions of lightyears away connected to us? Is our home nothing more than a tiny speck of blue in an ocean of night? In this exciting tour of a universe far larger than we can imagine, cosmologist Paul M. Sutter emphasizes how amazing it is that we are part of such a huge, complex, and mysterious place. Through metaphors and uncomplicated language, Sutter breathes life into the science of astrophysics, unveiling how particles, forces, and fields interplay to create the greatest of cosmic dramas. Touched with the author's characteristic breezy, conversational style--which has made him a breakout hit on venues such as The Weather Channel, the Science Channel, and his own popular Ask a Spaceman! podcast--he conveys the fun and wonder of delving deeply into the physical processes of the natural universe. He weaves together the past and future histories of our universe with grounded descriptions of essential modern-day physics as well as speculations based on the latest research in cosmology. Topics include our place in the Milky Way galaxy; the cosmic web--a vast web-like pattern in which galaxies are arranged; the origins of our universe in the big bang; the mysteries of dark matter and dark energy; how science has dramatically changed our relationship to the cosmos; conjectures about the future of reality as we know it; and more.For anyone who has ever stared at the starry night sky and wondered how we humans on Earth fit into the big picture, this book is an essential roadmap.




Astrophysical Applications of Gravitational Lensing


Book Description

EDWIN TURNER AND RACHEL WEBSTER Co-Chairs, Scientific Organizing Committee lAU Symposium 173, Astrophysical Applications of Gravitational Lenses, was held in Melbourne, Australia from July 9-14, 1995. The Symposium was sponsored by lAU Commissions 47 and 40. With the discovery by Walsh and collaborators of the first instance of a gravitational lens, the multiply imaged quasar 0957+561, the area of grav itational lensing moved from speculative theory to a major astrophysical tool. Since that time, there have been regular, approximately biennial in ternational meetings both in Europe and in North America, which have specifically focussed on gravitational lensing. On this occasion, with the blessing of the lA U, the meeting was held at the University of Melbourne in Australia. It was the first international astronomical meeting to be held at the University of Melbourne, and hope fully has given the astronomical community some enthusiasm for trekking half-way round the globe to Australia to discuss their latest work.




Merging Processes in Galaxy Clusters


Book Description

Mergers are the mechanisms by which galaxy clusters are assembled through the hierarchical growth of smaller clusters and groups. Major cluster mergers are the most energetic events in the Universe since the Big Bang. Many of the observed properties of clusters depend on the physics of the merging process. These include substructure, shock, intra cluster plasma temperature and entropy structure, mixing of heavy elements within the intra cluster medium, acceleration of high-energy particles, formation of radio halos and the effects on the galaxy radio emission. This book reviews our current understanding of cluster merging from an observational and theoretical perspective, and is appropriate for both graduate students and researchers in the field.




The Shapes of Galaxies and Their Dark Halos


Book Description

This book constitutes the proceedings of a very topical workshop aimed at understanding the shapes of the baryonic and dark matter components of galaxies. Several groups presented their recent results from observations and numerical N-body simulations.




Encyclopedia of the Solar System


Book Description

Long before Galileo published his discoveries about Jupiter, lunar craters, and the Milky Way in the Starry Messenger in 1610, people were fascinated with the planets and stars around them. That interest continues today, and scientists are making new discoveries at an astounding rate. Ancient lake beds on Mars, robotic spacecraft missions, and new definitions of planets now dominate the news. How can you take it all in? Start with the new Encyclopedia of the Solar System, Second Edition.This self-contained reference follows the trail blazed by the bestselling first edition. It provides a framework for understanding the origin and evolution of the solar system, historical discoveries, and details about planetary bodies and how they interact—and has jumped light years ahead in terms of new information and visual impact. Offering more than 50% new material, the Encyclopedia includes the latest explorations and observations, hundreds of new color digital images and illustrations, and more than 1,000 pages. It stands alone as the definitive work in this field, and will serve as a modern messenger of scientific discovery and provide a look into the future of our solar system.· Forty-seven chapters from 75+ eminent authors review fundamental topics as well as new models, theories, and discussions· Each entry is detailed and scientifically rigorous, yet accessible to undergraduate students and amateur astronomers· More than 700 full-color digital images and diagrams from current space missions and observatories amplify the chapters· Thematic chapters provide up-to-date coverage, including a discussion on the new International Astronomical Union (IAU) vote on the definition of a planet· Information is easily accessible with numerous cross-references and a full glossary and index




Unveiling Galaxies


Book Description

A thought provoking study of the powerful impact of images in guiding astronomers' understanding of galaxies through time.