E. KONTIZAS Astronomical Institute National Observatory of Athens P. O. Box 20048 Athens GR-1181O GREECE The international conference on "Wide-Field Spectroscopy" and its sub ject matter were agreed during the general assembly of the International Astronomical Union (IAU) in August 1994 by the Working Group of Com mision 9 "Wi de-Field Imaging". This meeting gave an opportunity to world experts on this subject to gather in Athens, in order to discuss the cur rent exploitation and the impending opportunities that exist in the area of multi-object spectroscopy, with particular emphasis on: 1. Astronomical instruments, data acquisition, processing and analysis techniques. 2. Astrophysical problems best tackled through wide-field, multi-object spectroscopy. The new fibre optic technology offers an important tool for the advancement of basic research and the development of industrial applications. Astronom ical spectroscopy is a field of astronomy which has contributed much to the advancement of fundamental physics. The spectra of hot stars have been used to determine the well-known Balmer formula for the wavelength of hydrogen lines, in the late 19th century. Since then, spectroscopy has made enormous progress in stellar atmosphere studies, in kinematics, and in the detection of high redshifts in the Universe. The traditional techniques of obtaining wide-field spectroscopic data are based on slitless spectroscopy (objective prism). Several observations, world wide, make use ofthese tech niques in order to obtain information on the spectral properties of objects in large areas of the sky.

H.T. MacGilLIVRAY Royal Observatory Blackford Hill Edinburgh EH9 3HJ Scotland U.K. lAU Symposium No. 161 on 'Astronomy from Wide-Field Imaging', held in Potsdam, Germany, during 23-27th August 1993, was the first conference organised by the recently-formed Working Group of lAU Commission 9 on 'Wide-Field Imaging'. This Working Group was instigated during the XXIst meeting of the General Assembly of the International Astronomical Union in Buenos Aires in 1991, and represented a merging of the former formal lAU Working Group on 'Astronomical Photography' and the informal 'Digitised Optical Sky Surveys' Working Group. Dr. Richard West was 'invited' to be Chairperson, and hence was given the daunting task of organising the Group from scratch. The very fact that the first conference after only two years was a major lAU Symposium says much about the determination and enthusiasm of Richard West to fulfilling the aims of the new Working Group. The siting of the conference in Potsdam in formerly East Germany provided an excellent opportunity to advantage from the political changes in Eastern Europe. Good access to the meeting was possible by scientists from Eastern European countries, allowing exchange of information on the very important Wide-Field facilities in both East and West, information on the rich archives of photographic plates that exist in both East and West, and allowing discussions between scientists facing very similar problems in both East and West.

Proceedings volume for researchers and graduate students of astronomy, covering the most exciting science and key ELT projects.

Over the last 50 years, a variety of techniques have been developed to add a third dimension to regular imaging, with an extended spectrum associated to every imaging pixel. Dubbed 3D spectroscopy from its data format, it is now widely used in the astrophysical domain, but also inter alia for atmospheric sciences and remote sensing purposes. This is the first book to comprehensively tackle these new capabilities. It starts with the fundamentals of spectroscopic instruments, in particular their potentials and limits. It then reviews the various known 3D techniques, with particular emphasis on pinpointing their different `ecological? niches. Putative users are finally led through the whole observing process, from observation planning to the extensive ? and crucial - phase of data reduction. This book overall goal is to give the non-specialist enough hands-on knowledge to learn fast how to properly use and produce meaningful data when using such a 3D capability.

Time-correlated Single Photon Counting has been written in the hope that by relating the authors' experiences with a variety of different single photon counting systems, they may provide a useful service to users and potential users of this formidably sensitive technique. Of all the techniques available to obtain information on the rates of depopulation of excited electronic singlet states of molecular species, monitoring of fluorescence provides, in principle, the simplest and most direct measure of concentration. This volume comprises eight chapters, with the first focusing on the time dependence and applications of fluorescence. Succeeding chapters go on to discuss basic principles of the single photon counting lifetime measurement; light sources; photomultipliers; electronics; data analysis; nanosecond time-resolved emission spectroscopy; time dependence of fluorescence anisotropy. This book will be of interest to practitioners in the field of chemistry.