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.

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

The Workshop “Science with the VLT in the ELT Era” held in Garching from 8th to 12th October 2007 was organised by ESO, with support from its Scienti c and Technical Committee, to provide a forum for the astronomical community to debate the long term future of ESO’s Very Large Telescope (VLT) and its interferometric mode (VLTI). In particular it was considered useful for future planning to evaluate how its science use may evolve over the next decade due to competition and/or synergy with new facilities such as ALMA, JWST and, hopefully, at least one next generation 30–40 m extremely large telescope whose acronym appears in the title to symbolise this wider context. These discussions were also held in the fresh light of the Science Vision recently developed within ASTRONET as the rst step towards a 20 year plan for implementing astronomical facilities—the rst such attempt within Europe. Speci c ideas and proposals for new, second generation VLT/I instruments were also solicited following a tradition set by several earlier Workshops held since the start of the VLT development. The programme consisted of invited talks and reviews and contributed talks and posters. Almost all those given are included here although, unfortunately not the several lively but constructive discussion sessions.

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.

This is the start of a long process to ultimately operate new advanced capabilities at Paranal that can keep up with the evergrowing need for larger and more complex astrophysical data sets. A modern instrument represents a very significant investment in cash, human resources and time. Such a meeting gives us a precious yardstick to evaluate the competitiveness of 1st-generation instruments and associated current and forthcoming proposals for 1st-generation upgrades. This is also crucial to orient the large research and development effort that will provide the very foundation on which 2nd-generation VLT instrumentation can be built. Finally, it represents a significant step towards defining the hopes and goals for the future Extremely Large Telescope to come. The first outcome of this meeting, already in progress, is outlined in the epilogue.

Galaxies represent the most readily visible fabric of the cosmos. Their morphological types, luminosities and environmental surroundings contain valuable clues as to their origin and evolution. Locally, a strong correlation is seen between galaxy morphology and environmental location; this may have been molded at surprisingly modest redshifts. Spectroscopic and photometric studies of deep fields also suggest remarkably recent changes in the galaxy population. The associated growth of structure during the same interval can be tracked via X-ray studies of distant clusters of galaxies.Very recently, impressive observational facilities have been completed, each of which has extended the astronomers' dataset to look-back times where such evolutionary effects can be studied.This volume discusses surveys which share a common theme — the need for a large number of ground-based spectra. It focuses on the various approaches via a single theme concerned with the evolution of galaxies and their distribution. In the near future, impressive new observational facilities will be able to generate large statistical spectroscopic surveys, and the aim of this volume is to assess the scientific impact that ongoing and future spectroscopic surveys can make. Emphasis is placed on the role of non-optical and satellite facilities and the co-ordination of international efforts.