Cosmic Gamma Rays, Neutrinos, and Related Astrophysics


Book Description

Proceedings of the NATO Advanced Study Institute, Erice, Sicily, Italy, April 20-30, 1988




Astronomy with Radioactivities


Book Description

This book introduces the reader to the field of nuclear astrophysics, i.e. the acquisition and reading of measurements on unstable isotopes in different parts of the universe. The authors explain the role of radioactivities in astrophysics, discuss specific sources of cosmic isotopes and in which special regions they can be observed. More specifically, the authors address stars of different types, stellar explosions which terminate stellar evolutions, and other explosions triggered by mass transfers and instabilities in binary stars. They also address nuclear reactions and transport processes in interstellar space, in the contexts of cosmic rays and of chemical evolution. A special chapter is dedicated to the solar system which even provides material samples. The book also contains a description of key tools which astrophysicists employ in those particular studies and a glossary of key terms in astronomy with radioactivities.




Very High Energy Cosmic Gamma Radiation


Book Description

Gamma ray astronomy, the branch of high energy astrophysics that studies the sky in energetic Ýgamma¨-ray photons, is destined to play a crucial role in the exploration of nonthermal phenomena in the Universe in their most extreme and violent forms. This book presents the motivations and highlights the principal objectives of the field, as well as demonstrates its intrinsic links to other branches of high energy astrophysics. Preference is given to three topical areas: (i) origin of cosmic rays: (ii) physics and astrophysics of relativistic jets: (iii) observational gamma ray cosmology. Also, a significant part of the book is devoted to the discussion of the principal mechanisms of production and absorption of energetic Ýgamma¨-rays in different astrophysical environments, as well as to the description of the detection methods of high energy cosmic Ýgamma¨- radiation.




Cosmic Rays at Earth


Book Description

In 1912 Victor Franz Hess made the revolutionary discovery that ionizing radiation is incident upon the Earth from outer space. He showed with ground-based and balloon-borne detectors that the intensity of the radiation did not change significantly between day and night. Consequently, the sun could not be regarded as the sources of this radiation and the question of its origin remained unanswered. Today, almost one hundred years later the question of the origin of the cosmic radiation still remains a mystery.Hess' discovery has given an enormous impetus to large areas of science, in particular to physics, and has played a major role in the formation of our current understanding of universal evolution. For example, the development of new fields of research such as elementary particle physics, modern astrophysics and cosmology are direct consequences of this discovery. Over the years the field of cosmic ray research has evolved in various directions: Firstly, the field of particle physics that was initiated by the discovery of many so-called elementary particles in the cosmic radiation. There is a strong trend from the accelerator physics community to reenter the field of cosmic ray physics, now under the name of astroparticle physics. Secondly, an important branch of cosmic ray physics that has rapidly evolved in conjunction with space exploration concerns the low energy portion of the cosmic ray spectrum. Thirdly, the branch of research that is concerned with the origin, acceleration and propagation of the cosmic radiation represents a great challenge for astrophysics, astronomy and cosmology. Presently very popular fields of research have rapidly evolved, such as high-energy gamma ray and neutrino astronomy. In addition, high-energy neutrino astronomy may soon initiate as a likely spin-off neutrino tomography of the Earth and thus open a unique new branch of geophysical research of the interior of the Earth. Finally, of considerable interest are the biological and medical aspects of the cosmic radiation because of it ionizing character and the inevitable irradiation to which we are exposed. This book is a reference manual for researchers and students of cosmic ray physics and associated fields and phenomena. It is not intended to be a tutorial. However, the book contains an adequate amount of background materials that its content should be useful to a broad community of scientists and professionals. The present book contains chiefly a data collection in compact form that covers the cosmic radiation in the vicinity of the Earth, in the Earth's atmosphere, at sea level and underground. Included are predominantly experimental but also theoretical data. In addition the book contains related data, definitions and important relations. The aim of this book is to offer the reader in a single volume a readily available comprehensive set of data that will save him the need of frequent time consuming literature searches.




High Energy Radiation from Black Holes


Book Description

Beginning with Einstein's special and general theories of relativity, the authors give a detailed mathematical description of fundamental astrophysical radiation processes, including Compton scattering of electrons and photons, synchrotron radiation of particles in magnetic fields, and much more.




Cosmic Gamma Rays


Book Description

Cosmic gamma ray production processes, galactic and extragalactic gamma rays, and cosmology.




A Study of the Sensitivity of an Imaging Telescope (Grits) for High Energy Gamma-Ray Astronomy


Book Description

When a gamma-ray telescope is placed in Earth orbit, it is bombarded by a flux of cosmic protons much greater than the flux of interesting gammas. These protons can interact in the telescope's thermal shielding to produce detectable gamma rays, most of which are vetoed. Since the proton flux is so high, the unvetoed gamma rays constitute a significant background relative to some weak sources. This background increases the observing time required to pinpoint some sources and entirely obscures other sources. Although recent telescopes have been designed to minimize this background, its strength and spectral characteristics were not previously calculated in detail. Monte Carlo calculations are presented which characterize the strength, spectrum and other features of the cosmic proton background using FLUKA, a hadronic cascade program. Several gamma-ray telescopes, including SAS-2, EGRET and the Gamma Ray Imaging Telescope System (GRITS), are analyzed, and their proton-induced backgrounds are characterized. In all cases, the backgrounds are either shown to be low relative to interesting signals or suggestions are made which would reduce the background sufficiently to leave the telescope unimpaired. In addition, several limiting cases are examined for comparison to previous estimates and calibration measurements. Yearian, Mason R. Unspecified Center...




Shock-Cloud Interaction in RX J1713.7−3946


Book Description

This book presents a study of the young supernova remnant RX J1713.7-3946 in order to reveal the origin of cosmic rays in our galaxy. The study focuses on the X-ray and gamma radiation from the cosmic ray electrons and protons in the supernova remnant as well as the emission from the surrounding interstellar gas measured by the NANTEN2 4-m radio telescope at Nagoya University. The gamma rays show a good spatial correspondence with the interstellar gas, which for the first time provides strong evidence of the acceleration of cosmic ray protons. Additionally, the author determines that an interaction between the supernova shockwaves and interstellar gas, referred to as “shock-cloud interaction,” promotes the efficient acceleration of cosmic ray electrons in the supernova remnant. The book reveals that the interstellar gas plays an essential role in producing the high-energy radiation and cosmic rays, offering vital new insights into the origin and behavior of galactic cosmic rays.