Richard M. West - Böcker

The importance of wide-field imaging in astronomy has never been so evident. The deep photographic surveys of the sky are nearing completion. The advent of large-format solid state detectors will provide further deep digital sky survey data. Optical surveys of the sky are being complemented by surveys in other wavebands of the electromagnetic spectrum, principally in the X-ray and near-infrared. The mass of digital data being gathered is driving the need for mass-storage archival capability, and for rapid capabilities in data acquisitioning and processing. New techniques are being developed to optimize the extraction of the information content. The quality and quantity of data now available to astronomers are enabling new breakthroughs in many fields, such as studies of the structure of our own galaxy and properties of nearby galaxies, the large-scale distribution of galaxies and the nature of the mass-content of the Universe. These facets of wide-field astronomy are brought together in this book.

The importance of wide-field imaging in astronomy has never been so evident. The deep photographic surveys of the sky are nearing completion. The advent of large-format solid state detectors will provide further deep digital sky survey data. Optical surveys of the sky are being complemented by surveys in other wavebands of the electromagnetic spectrum, principally in the X-ray and near-infrared. The mass of digital data being gathered is driving the need for mass-storage archival capability, and for rapid capabilities in data acquisitioning and processing. New techniques are being developed to optimize the extraction of the information content. The quality and quantity of data now available to astronomers are enabling new breakthroughs in many fields, such as studies of the structure of our own galaxy and properties of nearby galaxies, the large-scale distribution of galaxies and the nature of the mass-content of the Universe. These facets of wide-field astronomy are brought together in this book.

The XVlllth General Assembly of the International Astronomical Union was held in Patras, Greece, from 17-26 August 1982. It was marked by the tragic death of the President of the IAU, Professor M.K.V. Bappu, on August 19, 1982. This sad event, without precedent in the history of the Union, posed serious problems to the organization of the General Assembly, which could only be overcome by the full collaboration of all members, the organizers, and the Executive Committee. A tribute to the memory of Prof. Bappu was paid during a plenary meeting on 23 August 1982. The full texts of the speeches are published in Chapter I of this . volume. The excellent scientific programme in Patras was organized by the Presidents of the 40 IAU Commissions and coordinated by the IAU General Secretary (1979-1982), Professor P.A. Wayman. The local arrangements were taken care of by Professor C. Goudas and his collaborators from the Patras University. Due to the unexpected withdrawal in 1979 of another invitation to host the 1982 IAU General Assembly, the organizers in Greece had less than two years available for the extensive preparations, and our hearty thanks are due to them for their persistent efforts, which made this General Assembly an outstanding success.

Even the casual reader cannot fail to notice the somewhat uneven presentation of the contributions contributians to this volume, in particular what concerns the st style. yle. A closer scrutiny will also reveal that whereas the English language is certainly the preferred vehicle for commu- nication in astronomy, it is not the mother tongue of all contributors. However, while editing this volume I have felt that it would be more important to assure a speedy publication than to attempt to achieve a high degree of uniformity, which would anyhow be extremely diffi- cult with more than 100 eontributing contributing authors. When published, this book should stiIl still be a tool for aetive active research, not a museum pieee. piece. I am grateful to the organizers and editors of the individual sections seetions for having produced produeed their parts with within in the allotted time, and with a high degree of professionalism. A special speeial word of thanks goes to my eollaborators collaborators at the European Southern Observatory, Mrs. E. Volk, Volk, Mr. Nr. C. Madsen, and Mr. J. _Leelereqz, _Leclercqz, for technical teehnieal assistanee. assistance.

Even the casual reader cannot fail to notice the somewhat uneven presentation of the contributions contributians to this volume, in particular what concerns the st style. yle. A closer scrutiny will also reveal that whereas the English language is certainly the preferred vehicle for commu- nication in astronomy, it is not the mother tongue of all contributors. However, while editing this volume I have felt that it would be more important to assure a speedy publication than to attempt to achieve a high degree of uniformity, which would anyhow be extremely diffi- cult with more than 100 eontributing contributing authors. When published, this book should stiIl still be a tool for aetive active research, not a museum pieee. piece. I am grateful to the organizers and editors of the individual sections seetions for having produced produeed their parts with within in the allotted time, and with a high degree of professionalism. A special speeial word of thanks goes to my eollaborators collaborators at the European Southern Observatory, Mrs. E. Volk, Volk, Mr. Nr. C. Madsen, and Mr. J. _Leelereqz, _Leclercqz, for technical teehnieal assistanee. assistance.

The XVlllth General Assembly of the International Astronomical Union was held in Patras, Greece, from 17-26 August 1982. It was marked by the tragic death of the President of the IAU, Professor M.K.V. Bappu, on August 19, 1982. This sad event, without precedent in the history of the Union, posed serious problems to the organization of the General Assembly, which could only be overcome by the full collaboration of all members, the organizers, and the Executive Committee. A tribute to the memory of Prof. Bappu was paid during a plenary meeting on 23 August 1982. The full texts of the speeches are published in Chapter I of this . volume. The excellent scientific programme in Patras was organized by the Presidents of the 40 IAU Commissions and coordinated by the IAU General Secretary (1979-1982), Professor P.A. Wayman. The local arrangements were taken care of by Professor C. Goudas and his collaborators from the Patras University. Due to the unexpected withdrawal in 1979 of another invitation to host the 1982 IAU General Assembly, the organizers in Greece had less than two years available for the extensive preparations, and our hearty thanks are due to them for their persistent efforts, which made this General Assembly an outstanding success.

There is hardly any field of human endeavour which is more fundamental than the study of our surroundings. We have always wanted to learn what was behind our horizon, beyond the next mountain, on the other side of the ocean, on the next planet, at the end of the Universe. We have come a long way since our early ancestors gazed upon the sky in amazement. Giant optical and radio telescopes now allow us to "see" the early epochs of the Universe, revealing phenomena beyond our comprehension. Spacecrafts with on-board astronomical instrumentation circle the Earth and fly to the limits of the Solar System, providing invaluable new information about nearby and distant objects. Many people have the intuitive feeling that it is "easier and better" to study the Universe from above the Earth's atmosphere. However, this is only partially true in as much as electromagnetic radiation of certain wavelengths (e.g. X-rays) does not penetrate the atmosphere and can only be studied from balloons and space crafts • The advent of space-borne astronomy has not made ground-based observations obsolete - on the contrary, it is only thanks to the combination of the two that we have now a vastly more comprehensive picture of the Universe than just a few decades ago.