Bøger af G. Setti

This volume contains a series of lectures presented at the 4th Course of the International School of Astrophysics, held in Erice (Sicily) from July 9 - July 20, 1977 at the "E. Majorana" Centre for Scientific Culture. The course was fully supported by a grant from the NATO Advanced Study Institute Programme. It was attended by 82 participants from 15 countries. Even though the infrared portion of the electromagnetic spectrum covers an extensive interval from the red region of the optical spectrum (10,000 A) to the microwave radio region (1 mm), its role in astronomy has been minimal until the last two decades. Until very recently, the only objects observed were the sun, the moon and the planets. A primary reason for this late development was the lack of sensitive detectors and the necessary cryogenic technology that must accompany their use. Recent progress in this technology has been paralleled by an ever increasing interest of astronomers in infrared observations, leading to a number of ex­ tremely important results in different branches of astronomy. This becomes evident when one realizes that in many astrophysical conditions most of the energy is found to be channeled into the infrared portion of the electromagnetic spectrum. Stars were detected that yield most of their radiation in the infrared; these objects present a new view of stellar evolution, both in the birth and death stages.

The cosmic radiation was discovered by Hess in 1912 but its origin is still the subject of much controversy and considerable study. For several decades most workers in the cosmic ray field were interested in the Nuclear Physical aspect of the particle beam and many important dis­ coveries were made, notably the identification of the positron, the muon, the pion and the strange particles. More recently however, em­ phasis has changed to the Astrophysical aspect both with re8ard to the origin of the radiation and to its relation with the other radiation fields. Mindful of the increasing importance of the Astrophysical facets of the subject the Cosmic Ray Commission of IUPAP approached the High Energy Astrophysics Commission of the IAU with the suggestion of a joint Symposium on Cosmic Ray Origin. The plan was to bring together workers in all the various astronomical fields - from Radio, through Optical to Gamma Rays - with Cosmic Ray physicists and to fully explore the various interrelations. The approach was received with enthusiasm and this book contains the proceedings of the ensuing Symposium, (styled IUPAP/ IAU Symposium No. 94) which was held in Bologna from 11th - 14th June 1980. Virtually all the papers presented are reproduced here. The Scientific Organizing Committee chose the invited speakers whose papers formed the major scientific component of the meeting. Additional short contributed papers were also called for and very brief 2-page resumes (which have not been refereed) are given in the proceedings.

This volume contains a series of lectures delivered at the 2nd course of the International School of Astrophysics at the "Ettore Majorana" Centre for Scientific Culture in Erice (Sicily) from June 22 to July 9, 1974. The course was jointly planned by L. Woltjer and myself and was fully supported by a grant from the NATO Advanced Study Institute Programme. It was organized with the aim of providing students and young researchers with an up to date account of the structure and evolution of galaxies and was attended by 94 participants from 20 countries. The study of galaxies is one of the most important areas of contemporary astrophysics both for its intrinsic interest and because it is a prerequisite to a quantitative understanding of the structure of the universe. Recently, a qualitatively new under­ standing has become available through both observational andtheore­ tical progress. On the observational side, new techniques applied at the large optical telescopes and, in particular, the impressive results obtained wi. th the high resolution radio telescopes have made it possible to obtain a detailed mapping of the structure of galaxies other than our own. At the same time, new theoretical insights and the availability of powerful computers to construct models holds out the hope that a full understanding of the structur. es of galaxies may be within our reach.

Proceedings of the NATO Advanced Study Institute, Urbino, Italy, June 29-July 13, 1975