This is the second ESO workshop in aseries dedicated to science oppor tunities with the VLT. At the first workshop all areas of astronomical research were discussed. This second workshop is dedicated to research projects on the early Universe and has provided a forum for discussing strategies for studying faint distant objects in the optical and infrared spectral regions. This field is evolving very rapidly. There are several new surveys of galax ies and clusters of galaxies at intermediate redshift and quasars at very high redshift. Major advances in the morphological studies of distant galaxies, surveys of galaxies at high redshift and searches for primeval galaxies have been rendered possible by the new facilities provided by the Rubble Space Telescope and the Keck Telescope. Observational constraints on the evolution and formation of galaxies and large-scale structures as well as the cosmic chemical evolution were criti cally discussed with regard to theory and numerical simulations. In this context, the VLT first generation instrument capabilities were presented comprehensively and their use as cosmological tools discussed . The concluding remarks of the workshop focussed on the analysis of var ious possibilities for the VLT second generation instrumentation. Many of these topics were covered by invited reviews and talks, as well as some contributed talks. They are included in this volume together with the poster papers.

This book is a synopsis of modern deep-field astronomy, based on the powerful telescopes and instruments developed in recent years. It is organized along topical themes, such as the extragalactic background radiation at different wavelengths, the evolution of galaxies, the history of star formation, the nature of absorbers, the reionization of the intergalactic medium, the validity of photometric redshifts, gravitational lensing, and clustering of galaxies. Stellar and substellar objects were not neglected, however, and one session was devoted to nearby bodies such as trans-Neptunian solar system objects, brown dwarfs, and stars with special characteristics.

Understanding the largest physical structures in the universe is essential for the comprehension of the cosmos as a whole. We want to know how our world is formed, what it is made of and how it evolves.Galaxies, as the most visible constituents of the universe, are interesting probes for the cosmic time sequence. Their formation and development provides us with unique clues to the cosmic evolution. This is tightly connected with the hierarchical cosmic structure: groups and clusters of galaxies and their embedding into the large scale structure offer the opportunity to study the dependencies.Galaxy redshift surveys delineate most impressively a large cosmic web, which is composed of sheets and filaments. Grand simulations of the cosmic evolution complement these observations from the theoretical side and allow one quantify and compare various model universes.Quasar absorption line studies, gravitational lensing and even the X-ray background radiation provide important quantitative measures of the history of matter clustering. Finally, the microwave radiation traces very early structures, which are supposed to originate in the phase of inflationary expansion shortly after the big bang.This volume constituting the proceedings of the 12th Potsdam Cosmology Workshop, deals with the basic aspects of cosmological structure formation on the largest physical scales.

An Astronomical Life – Observing the Depths of the Universe” Though science as a subject can be di?cult, what has been more important for me is that its practice can also be rewarding fun! This book is crafted to expose the reader to the excitement of modern observational cosmology through the study of galaxy evolution over space and cosmic time. Recent extragalactic research has led to many rapid advances in the ?eld. Even a suitable skeptic of certain pronouncements about the age and structure of the Universe should be pleased with the large steps that have been taken in furthering our understanding of the Universe since the early 1990’s. My personal involvement in galaxy research goes back to the 1960’s. At that point, galaxies were easily recognized and partially understood as organized c- lections of stars and gas. What their masses were presented a problem, which I supposed would just fade away. But fade it didn’t. Distant active nuclei and quasars were discovered in the mid-1960’s. A c- mon view of QSOs was that they have large redshifts, but what use are they for cosmology or normal galaxy astrophysics? I shared that conclusion. My expec- tions fell below their potential utility. In short, the Universe of our expectations rarely matches the Universe as it is discovered.

Large area sky surveys are now a reality in the radio, IR, optical and X-ray passbands. In the next few years, new surveys using optical, UV and IR mosaic cameras with high throughput digital detectors will expand the dynamic range and accuracy of photometry and astrometry of objects over a significant fraction of the entire sky. Parallel X-ray and radio surveys over the same areas will produce astronomical image and spectroscopic databases of unprecedented size and quality. The combined data sets will provide significant new constraints on star formation, stellar dynamics, Galactic structure, the evolution of galaxies and large scale structure, as well as new opportunities to identify rare objects in the solar system and the Galaxy. Large area surveys have formidable data acquisition, processing, archiving, and data distribution demands and this meeting provided a forum for sharing experiences amongst workers specializing in different wavebands as well as discussing how multiband observations can reveal fundamental relationships in our understanding of the Universe.