Evidence for Shock Acceleration in the Binary Pulsar System PSR B1259-63


Book Description

The PSR B1259-63 system (Johnston et al. 1992, 1994) was observed near periastron by the Compton Gamma-Ray Observatory in January 1994. This system contains a rapidly rotating pulsar and a Be star in a highly eccentric binary orbit. We report the discovery by the OSSE instrument of unpulsed emission with a hard power-law spectrum between 50 and 200 keV from the direction of this system. Neither diffuse galactic background emission nor nearby X-ray binaries contribute significant to the detected flux. Our results are particularly important for the theory of interaction of pulsars with gaseous environments. We interpret the hard X-ray emission as synchrotron radiation from relativistic particles of the PSR B1259-63 wind being shocked and accelerated within the binary. Our results indicate, for the first time in a binary pulsar, that shock acceleration can increase the original energy of pulsar wind particles by a factor> but similar to 10, despite the high synchrotron and inverse Compton cooling rates near periastron. The derived shock properties (efficiency, radiation spectrum, timescale) are relevant for a broad class of high-energy astrophysical sources characterized by shocked relativistic plasmas subject to strong radiative cooling.




Modelling Pulsar Wind Nebulae


Book Description

In view of the current and forthcoming observational data on pulsar wind nebulae, this book offers an assessment of the theoretical state of the art of modelling them. The expert authors also review the observational status of the field and provide an outlook for future developments. During the last few years, significant progress on the study of pulsar wind nebulae (PWNe) has been attained both from a theoretical and an observational perspective, perhaps focusing on the closest, more energetic, and best studied nebula: the Crab, which appears in the cover. Now, the number of TeV detected PWNe is similar to the number of characterized nebulae observed at other frequencies over decades of observations. And in just a few years, the Cherenkov Telescope Array will increase this number to several hundreds, actually providing an essentially complete account of TeV emitting PWNe in the Galaxy. At the other end of the multi-frequency spectrum, the SKA and its pathfinder instruments, will reveal thousands of new pulsars, and map in exquisite detail the radiation surrounding them for several hundreds of nebulae. By carefully reviewing the state of the art in pulsar nebula research this book prepares scientists and PhD students for future work and progress in the field.




Millisecond Pulsars


Book Description

This book includes nine chapters written by internationally recognized experts, covering all aspects of millisecond pulsars in one concise and cohesive volume. These aspects include pulsations powered by stellar spin, accretion and thermonuclear burning of accreted matter, their physics and utility, stellar evolution and the extreme physics of super-dense stellar cores. The book includes substantial background material as well as recent theoretical and multi-wavelength observational results. The volume will thus be useful for professional astronomers and graduate students alike. What is the behavior of the strong nuclear interaction, and what are the matter constituents at ultrahigh densities in neutron star cores? How do old neutron stars in binaries evolve? How does their magnetosphere interact with the surrounding plasma to accelerate particles and emit radiation observed at all wavelengths? These are just a few of the questions that millisecond pulsars are helping us answer and will settle in the near future with the next generation of instruments. Such quickly rotating, highly magnetized neutron stars are remarkable natural laboratories that allow us to investigate the fundamental constituents of matter and their interactions under extreme conditions that cannot be reproduced in terrestrial laboratories.




Extreme Particle Acceleration in Microquasar Jets and Pulsar Wind Nebulae with the MAGIC Telescopes


Book Description

This exhaustive work sheds new light on unsolved questions in gamma-ray astrophysics. It presents not only a complete introduction to the non-thermal Universe, but also a description of the Imaging Atmospheric Cherenkov technique and the MAGIC telescopes. The Fermi-LAT satellite and the HAWC Observatory are also described, as results from both are included. The physics section of the book is divided into microquasars and pulsar wind nebulae (PWNe), and includes extended overviews of both. In turn, the book discusses constraints on particle acceleration and gamma-ray production in microquasar jets, based on the analyses of MAGIC data on Cygnus X-1, Cygnus X-3 and V404 Cygni. Moreover, it presents the discovery of high-energy gamma-ray emissions from Cygnus X-1, using Fermi-LAT data. The book includes the first joint work between MAGIC, Fermi-LAT and HAWC, and discusses the hypothetical PWN nature of the targets in depth. It reports on a PWN population study that discusses, for the first time, the importance of the surrounding medium for gamma-ray production, and in closing presents technical work on the first Large-Size-Telescope (LST; CTA Collaboration), along with a complete description of the camera.




Advances In Very High Energy Astrophysics: The Science Program Of The Third Generation Iacts For Exploring Cosmic Gamma Rays


Book Description

Very-high-energy astrophysics studies the most energetic photons in the sky, allowing the exploration of violent and extreme non-thermal phenomena in the Universe. Significant advances in knowledge have been made in this field using ground-based imaging atmospheric Cherenkov telescopes (IACTs) as detectors, to study these physical processes in the Universe. This book reviews the progress in the field since the advent of the second generation IACTs around 2004. Going through the scientific highlights obtained by the three current instruments of this kind, H.E.S.S., MAGIC and VERITAS, operating now for more than 15 years, this book presents a state-of-the-art knowledge in four areas of modern astrophysics and cosmology, namely the origin of the cosmic rays, the physics of compact objects and their resulting relativistic outflows, gamma-ray cosmology, and the search for dark matter. Along with a detailed review of the outstanding scientific outcomes, a summary of the key technological developments that yielded the recognized success of the technique is also provided.This book is written for early-career academics in the fields of astrophysics, high energy physics and cosmology. At the same time, it can serve as a source of reference for the expert in the field.







Astronomy and Astrophysics - Volume I


Book Description

Astronomy is the science of everything – with the exception of the Earth and everything on it and inside. Astronomy has a rich heritage dating back to the myths and legends of antiquity and the course of civilization has been greatly affected by mankind’s interpretation of what they saw in the starry sky and experienced through seasonal changes associated with the Sun and Moon. Early astronomy is associated with the definition of calendars which were needed to predict the dates of such as religious festivals and the numbers of months. A gradual shift of emphasis from astronomy to its sister, astrophysics, which took place through the 19th century, is generally attributed to the measurement of reliable stellar distances and the development of spectroscopy as a tool for understanding the physical nature of stars. Many paradigms in astronomy and its many subfields are continuously being shaken. New insights in the intricacy and elegance of the cosmos are steadily being obtained. Every few decennia, our concepts of the Universe are challenged and substantially modified. The reasons for this are the continuous development of new observing techniques and instruments for observatories both ground-based and in space, in addition to considerable progress in mathematics and physics, including computational ability. Our Universe harbors numerous phenomena and processes representing conditions that cannot be duplicated in terrestrial laboratories. Astronomy therefore frequently leads to fundamentally new insight and knowledge far beyond astronomy itself. Last but not least, it represents a first inspiring introduction to natural science, especially among young people, which is an extra motivation to many scientists to contribute to the Astronomy and Astrophysics Theme of this Encyclopedia. The book on Astronomy and Astrophysics with contributions from distinguished experts in the field, represents a first inspiring introduction to natural science, especially among young people, which is an extra motivation to many scientists to contribute to the Astronomy and Astrophysics Theme of this Encyclopedia. The first chapter which treats the development of astronomy and astrophysics in a historical perspective is followed by an account of the impact of astronomy on human culture and civilization. Observational astronomy is facing a number of environmental challenges. The nature and complexity of these and how the associated problems are met and overcome are described in the third article. Various aspects of our solar system are covered by authoritative articles on the Sun, planets including their satellites and smaller bodies, plus a review of the laws of motions and orbits of celestial bodies. The detection and studies of exo-solar planetary systems is rapidly developing field in astronomy which is treated in a separate chapter. Then follow fascinating up-to-date overviews on stars describing their formation, structure and life cycles. Stars are the building blocks of larger cosmic entities leading to the enigmatic galaxies composed of billions of stars, and gradually to clusters of galaxies. The final chapters cover the origin and evolution of galaxies and the large-scale structure of the Universe, including dark matter and dark energy which are among the most fascinating problems of physics today. These two volumes are aimed at the following five major target audiences: University and College students Educators, Professional practitioners, Research personnel and Policy analysts, managers, and decision makers and NGOs.