X- and gamma-ray astronomy : symposium no. 55 held in Madrid, Spain, 11-13 May 1972

The IAU Symposium No. 55 on 'X-Ray and Gamma-Ray Astronomy' has occurred, not entirely by coincidence, at an important moment in the development of these new branches of observational astronomy. In X-ray astronomy the data from the first X-ray observatory UHURU have contributed to a new view of the X-ray sky and a new conception of the nature and properties of galactic and extragalactic X-ray sources. In gamma-ray astronomy the exciting and often controversial nature of the results underlines the importance of the forthcoming launch of SAS-B, the first orbiting y-ray observatory. As Bruno Rossi reminds us (p. I), the Symposium occurred almost exactly ten years after the first detection of the X-ray star Sco X-I. During this time we have moved from the detection of a handful of the nearest and brightest sources to the detailed study of the nature of stellar sources in the farthest reaches of our own galaxy and in external galaxies of the local group. The detection of pulsating X-ray sources in bi­ nary systems permits the measurement of pulsation periods, and orbital parameters with precisions comparable to any yet achieved with traditional observational techniques. The strong indications that most X-ray sources are extremely compact objects give us confidence that X-ray astronomy will playa significant and possibly decisive role in the study of stars near the end point of stellar evolution. Front Matter....Pages i-x Introductory Remarks....Pages 1-6 Front Matter....Pages 7-7 UHURU Results on Galactic X-ray Sources....Pages 9-28 Observations of Cosmic X-ray Sources by the MIT Instrument on the OSO-7....Pages 29-35 Binary Systems as X-ray Sources: A Review....Pages 36-50 Hard Cosmic X-ray Sources....Pages 51-73 Simultaneous X-ray, Optical and Radio Observations of Galactic X-ray Sources....Pages 74-85 Radio Observations of X-ray Sources....Pages 86-97 Radio Counterparts of X-ray Sources and X-ray Counterparts of Radio Stars....Pages 98-104 X-Radiation from Supernova Remnants....Pages 105-117 Galactic X-ray Polarimetry and High-Resolution X-ray Spectroscopy....Pages 118-131 Front Matter....Pages 133-133 Models for Compact X-ray Sources....Pages 135-142 Models for Compact Pulsing X-ray Sources....Pages 143-154 Black Holes in Binary Systems: Observational Appearances....Pages 155-164 Pulsars and X-ray Sources....Pages 165-167 Front Matter....Pages 169-169 UHURU Results on Extragalactic X-ray Sources....Pages 171-183 The Properties of Extragalactic X-ray Sources from Visible Light Observations....Pages 184-198 Extragalactic X-ray Sources....Pages 199-207 Extragalactic X-ray Sources and Their Contribution to the Diffuse Background....Pages 208-211 Front Matter....Pages 213-213 The Soft X-ray Background....Pages 215-234 Absorption and Production of Soft X-rays in the Galaxy....Pages 235-249 Front Matter....Pages 213-213 ‘Evolutionary’ Theories of the X-ray Background....Pages 250-257 ‘Local’ Theories of the X-ray Background....Pages 258-275 Front Matter....Pages 277-277 Diffuse Background of Energetic X-rays....Pages 279-302 High-Energy Discrete Sources....Pages 303-323 Proceedings of IAU Symposium No. 55, held in Madrid, Spain, May 11-13, 1972