Background Due To Cosmic Protons In Gamma Ray Telescopes Final Report

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

After describing cosmic gamma-ray production and absorption, the instrumentation used in gamma-ray astronomy is explained. The main part of the book deals with astronomical results, including the somewhat surprising result that the gamma-ray sky is continuously changing.

Gamma ray astronomy, the branch of high energy astrophysics that studies the sky in energetic γ-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. The great potential of this discipline offers impressive coverage of many “hot topics” of modern astrophysics and cosmology, such as the origin of galactic and extragalactic cosmic rays, particle acceleration and radiation processes under extreme astrophysical conditions, and the search for dark matter. The recent observational results and exciting theoretical predictions provide a strong rationale for a deep study of cosmic radiation with forthcoming satellite-borne and ground-based detectors in the so-called very high energy domain of the electromagnetic spectrum above 1010 eV. This invaluable 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, an essential part of the book is devoted to the discussion of the principal mechanisms of production and absorption of energetic γ-rays in different astrophysical environments, as well as to the description of the detection methods of high energy cosmic γ-radiation. Contents:Status of the FieldGamma Ray Production and Absorption MechanismsGamma Rays and Origin of Galactic Cosmic RaysGamma Ray Visibility of Supernova RemnantsPulsars, Pulsar Winds, PlerionsGamma Rays Expected from MicroquasarsLarge Scale Jets of Radio Galaxies and QuasarsNonthermal Phenomena in Clusters of GalaxiesTeV Blazars and Cosmic Background RadiationHigh Energy Gamma Rays — Carriers of Unique Cosmological Information Readership: Astrophysicists, cosmic ray physicists, cosmologists and high energy physicists. Keywords:Reviews:“The author has been an active player in the pioneering experiments that opened the ‘last electromagnetic window’ at photon energies beyond GeV, or wavelengths smaller than 10–13 cm. This is a timely in-depth review of gamma ray astronomy, a field exploding with new instrumentation: space-borne detectors aiming for astronomy with thousands of sources and ground-based detectors hunting for the origin of the cosmic rays, still enigmatic one century after their discovery.”Francis Halzen University of Wisconsin “‘Very high-energy gamma-ray astronomy’ is now beginning to play a crucial role in understanding the high-energy phenomena in the Universe. Flix Ahranonian clearly describes the implication of this new developing field relating to Cosmic-ray Physics, X-ray and low energy gamma-ray astronomy, Potential Extragalactic sources and Cosmologies and dark matter … His writing covers what is known, what is to be explored in future, and also speculating on some new exciting unknown phenomena. He is one of the pioneers and a leading scientist in this field, and this book is timely and valuable for the students and researchers in this field which developed so quickly in recent years together with the scientists who have interest and wish to understand and research the high-energy phenomena in the Universe.”Emeritus Professor Jun Nishimura The University of Tokyo, and Institute of Space and Astronuatical Science “In the entire text Aharonian attaches importance to analytic descriptions. He outlined, discusses and quotes numerous model calculations as well as an abundance of experimental data. The Bibliography is very extensive. This is a recommendable book.”Physik Journal

Gamma-ray astronomy has undergone an enormous progress in the last 15 years. The success of satellite experiments like NASA's Comp ton Gamma-Ray Observatory and ESA's INTEGRAL mission, as well as of ground-based instruments have open new views into the high-energy Universe. Different classes of cosmic gamma-ray sources have been now detected at different energies, in addition to young radio pulsars and gamma-ray bursts, the classical ones. The new sources include radio quiet pulsars, microquasars, supernova remnants, starburst galaxies, ra dio galaxies, flat-spectrum radio quasars, and BL Lacertae objects. A large number of unidentified sources strongly suggests that this brief enumeration is far from complete. Gamma-ray bursts are now estab lished as extragalactic sources with tremendous energy output. There is accumulating evidence supporting the idea that massive stars and star forming regions can accelerate charged particles up to relativistic ener gies making them gamma-ray sources. Gamma-ray astronomy has also proved to be a powerful tool for cosmology imposing constraints to the background photon fields that can absorb the gamma-ray flux from dis tant sources. All this has profound implications for our current ideas about how particles are accelerated and transported in both the local and distant U niverse. The evolution of our knowledge on the gamma-ray sky has been so fast that is not easy for the non-specialist scientist and the graduate student to be aware of the full potential of this field or to grasp the fundamentals of a given topic in order to attempt some original contribution.