"Neutrinos and Explosive Events in the Universe" brought together experts from diverse disciplines to offer a detailed view of the exciting new work in this part of High Energy Astrophysics. Sponsored by NATO as an Advanced Study Institute, and coordinated under the auspices of the International School of Cosmic Ray Astrophysics (14th biennial course), the ASI featured a full program of lectures and discussion in the ambiance of the Ettore Majorana Centre in Erice, Italy, including visits to the local Dirac and Chalonge museum collections as well as a view of the cultural heritage of southern Sicily. Enri- ment presentations on results from the Spitzer Infrared Space Telescope and the Origin of Complexity complemented the program. This course was the best attended in the almost 30 year history of the School with 121 participants from 22 countries. The program provided a rich ex- rience, both introductory and advanced, to fascinating areas of observational Astrophysics Neutrino Astronomy, High Energy Gamma Ray Astronomy, P- ticle Astrophysics and the objects most likely responsible for the signals - plosions and related phenomena, ranging from Supernovae to Black Holes to the Big Bang. Contained in this NATO Science Series volume is a summative formulation of the physics and astrophysics of this newly emerging research area that already has been, and will continue to be, an important contributor to understanding our high energy universe.

This text comprises selected lectures presented in the 9th course of the International School of Cosmic-Ray Astrophysics held at the Ettore Majorana Centre in Erice, Sicily, May 7-18, 1994. Devoted to problems and prospects in high-energy astrophysics and cosmology, the major areas explored are: gamma- ray, X-ray, and neutrino astronomies; cosmic rays; pulsars and supernova remnants; and cosmology, as well as cosmogony. Among the principal developments in gamma-ray astrophysics are those generated by the Compton Gamma Ray Observatory. Cosmic neutrinos at MeV energies, i.e. those from the Sun and from Supernova 1987a are discussed, as well as neutrino masses in astrophysics. The source composition of cosmic rays and extensive air shower experiments receive special attention. The early universe according to COBE data, and as viewed by theorists of cosmology, is reviewed.

The symbiosis between particles physics and cosmology has virtually become a conjugal relationship. Hence the 9th Biennial Course of the International School of Cosmic-Ray Astrophysics was designed to bridge these formerly disparate disciplines. This NATO Advanced Study Institute took place at the Ettore Majorana Centre in Erice, Italy, June 20-30, 1992. Seventy participants from 17 countries participated in lively interactions and enjoyed the stimulating lectures that form the basis for this volume. The book includes current advances in both astrophysics (cosmic gamma ravs, X-rays, cosmic rays) and cosmology (an introduction to inflation in big-bang theory, the age of the universe, nucleosynthesis in the early universe). It is suitable for reading and study by all interested physical scientists, especially those having a limited specialized background in astrophysics and cosmology.

I. Cosmic Rays and the Interstellar Medium.- A Brief Introduction to the Cosmic Radiation.- The Composition of the Cosmic Rays: An Update.- Interstellar Dust-Gas Relationships.- Dust, Gas and Cosmic Rays in the Interstellar Medium.- Comparison Between Greenberg and Mathis Models of Grains for the H2 Formation Induced by Cosmic Rays.- II. Supernovae, Acceleration, Propagation and Source Composition.- Shock Acceleration of Cosmic Rays.- Source Composition, Sites of Origin And Acceleration of Cosmic Rays.- Cosmic-Ray Age and the Interstellar Medium.- The Production of Antiprotons in the Interstellar Gas by Propagating Cosmic Rays.- The Source Composition of Galactic Cosmic Rays and the Condensation Process of the Elements in Circumstellar and Interstellar Gases.- The Distribution of Supernova Remnants in the Galaxy.- Gamma Rays from Supernova 1987A.- Acceleration of Cosmic Rays at Young Supernova Remnants.- The Effect of Relativistic Particle Beams on the Evolution of Supernova Envelopes: Self-Consistent Solutions.- Radio Spectral Variations in the Cygnus Loop.- III. Gamma Rays and Their Role as Cosmic Ray Tracers.- Gamma Ray Astrophysics at Energies up to 10 Gev.- Vhe and UHE Gamma Ray Sources.- Gamma-Rays from Electron, Proton Beam Interactions with Matter and/or Radiation: Application to Cygx-L, Geminga, and 3C273.- Gamma Rays and Neutrinos from Accretion Processes onto Collapsed Objects: Application to 3C273.- Nearby Galaxies in Highenergy Gamma Rays.- IV. Ultra-Energetic Cosmic Nuclei.- Cosmic Rays at the Highest Energies.- Participants.- Author Index.