When falling into a galaxy cluster, the spiral - rich field galaxy population gets transformed into the characteristic E/S0/dE/dSph - rich cluster galaxy population and this already happens at surprisingly large galactocentric radii around $\sim$3R$_{virial}$. A variety of transformation processes are discussed, their respective importance and timescales. Their relations to the cluster properties, however, remain to be explored. Galaxy transformation processes, transition stages, and timescales can very well be explored by a comparison of deep multi-band imaging for a large fraction of the cluster galaxy population (down to M$^{\ast} + 3$ mag out to redshifts ${z \sim 0.5}$) and of spectroscopy of the brighter members with evolutionary synthesis models. SALT's large collecting area and field of view together with its unique $U$-band sensitivity are ideal in this respect.

The absorption lines seen in the spectra of high redshift QSOs are important tools for studying the early evolution of galaxies and intergalactic medium. In this presentation I briefly review various available observations, our understanding of different types of absorption systems, and highlight some of the issues that can be addressed with ELTs.

We discuss the opportunities to use the future ELTs to study in detail the properties and the evolution peculiarities of individual massive stars with a metal content typical of galaxies in the Universe during the first 0.5–1Gyr, corresponding to the earliest known newly formed galaxies at redshifts of $z$ = 6–10. This is possible in principle due to the existence in the local Universe of starbursting galaxies with metallicities of $\sim$1/30 Z$_{\odot}$. The nearest such galaxies are DDO 68 at $\sim$6.5 Mpc with 12+log(O/H) = 7.21 and I Zw 18 at 15 Mpc with 12+log(O/H) = 7.17. For the youngest star clusters (with ages of T $<$ 4–5Myr) in these most metal-poor galaxies, stars with masses up to 40–60 M$_{\odot}$ should be present on both the Main Sequence and the later evolution stages, including the WR stage. They are expected to have apparent magnitudes as bright as $V\,{=}\,21^m$ for DDO 68 and $V\,{=}\,23^m$ for I Zw 18. Good S/N-ratio spectroscopy with telescopes like OWL or JWST, allowing near-milli-arcsecond angular resolution, will provide unique information to check the most up-to-date models of massive star evolution in the very low metallicity regime, and thus, establish a firm basis to model the effects of star formation in ‘primordial’ galaxies, at the epoch of galaxy formation. Such observations will also provide an independent channel to probe the primordial Helium abundance.

Star formation in starbursts produces compact star clusters which extend in mass up to the super star clusters (SSCs) which resemble young globular clusters. Compact young massive star clusters (cYMCs) in turn cluster along with other young stars into starburst clumps. Using M82 as an example we briefly review how the presence of starburst clumps affects the evolution of the host galaxy. Extremely large telescopes (ELTs) will be essential for understanding how starburst clumps and their constituent star clusters evolve. In nearby systems their combination of sensitivity and angular resolution will allow us to explore the structures, kinematics, and abundances of cYMCs. For systems at cosmological distances the high surface brightnesses of the starburst clumps makes them prime gateways for exploring the early evolution of galaxies.

We present GALEV evolutionary synthesis models for Simple Stellar Populations (SSPs = single burst, single metallicity) like star clusters or galaxy pixels and for galaxies of various types on the basis of their respective typical star formation histories, ranging from exponentially declining on a timescale of 1Gyr for the classical elliptical model through constant for Sd galaxies, and also allowing for starbursts of various strengths occurring at various evolutionary stages. Models yield the time evolution of the stellar population in terms of color-magnitude diagrams CMDs ($U$\dots $K$), spectra (90Å…160$\mu$m) including gaseous emission in terms of lines and continuum, luminosities, colors and M/L-ratios in various filter systems (e.g. Johnson $U$\dots $K$, HST, Washington, Strömgren), and Lick indices (http://www.astro.physik.uni-goettingen.de/~galev). For galaxies, the redshift evolution is obtained from the time-evolving spectra assuming a standard cosmology (H$_0=65, \Omega_0=0.3, \Omega_{\Lambda}=0.7$) and consistently accounting for evolutionary and cosmological corrections as well as for the attenuation of light from distant galaxies by intervening HI.

The 100 m OWL ESO Concept Study has undergone a full review early November 2005. The development of the concept, the conclusions of the review panel and the planned post-review actions for the European Extremely Large Telescope (ELT) to be built by ESO in the next 10 years are presented and discussed.

The requirements on ELTs from the perspective of X-ray astronomy are explored. These requirements will be driven largely by deep X-ray surveys, like those conducted with XMM-Newton and the Chandra X-ray Observatory. Up to the present time, ground-based telescopes have largely kept abreast of the needs arising from deep X-ray surveys, i.e. the current generation of 10m-class telescopes is able to (barely) match the required spectroscopic needs for optical identifications in most cases (up to 70%). There are two X-ray astronomy facilities currently proposed and under study: the European-led X-ray Early Universe Spectroscopic mission (XEUS) and the NASA proposal Constellation-X. The emphasis of both these missions, like XMM-Newton, is X-ray spectroscopy, but they will both perform deep surveys which will need optical follow-up spectroscopy towards the middle or end of the next decade.

Various projects to find planets or entire planetary systems around main sequence stars in the solar neighborhood are presently under way. When ELTs will be operational, there will be literally thousands of confirmed planetary systems including spectro-photometric detections. At this point it becomes inevitable to consider the next logical step: the spectroscopic analysis of the atmospheres of these planets. High-resolution spectroscopy, i.e. resolving $v \times \sin (i)$ of these planets, in the wavelength regime of 950-5500nm is a powerful and promising tool. In view of the obvious contrast problems in detecting such planets non-LTE features are specifically targeted. Sensitivity estimates for the detection of the non-thermal OH glow in oxygen-bearing atmospheres are given. With 8m-class telescopes such a search is impossible, but a dedicated spectrograph, e.g. at the projected ESO 100m OWL telescope could detect Earth-like planets at a distance of ${\approx} 10$ parsec. A conceptual design for a dedicated spectrograph, NOCTUA, is presented. In case of ELTs of smaller size the science case changes and the instrument requirements have to be adjusted. Preparatory work with CRIRES, ESO's Cryogenic Infrared Echelle Spectrograph on the VLT at $\frac{\lambda}{\Delta \lambda} \approx 10^5$ as well as other science cases are shortly discussed.

Top of the wish list of any astronomer who wants to understand galaxy formation and evolution is to resolve the stellar populations of a sample of giant elliptical galaxies: to take spectra of the stars and make Colour-Magnitude Diagrams going down to the oldest main sequence turn-offs. It is only by measuring the relative numbers of stars on Main Sequence Turnoffs at ages ranging back to the time of the earliest star formation in the Universe that we can obtain unambiguous star formation histories. Understanding star formation histories of individual galaxies underpins all our theories of galaxy formation and evolution. To date we only have detailed star formation histories for the nearest objects in the Local Group, namely galaxies within 700kpc of our own. This means predominantly small diffuse dwarf galaxies in a poor group environment. To sample the full range of galaxy types and to consider galaxies in a high density environment (where much mass in the Universe resides) we need to be able to resolve stars at the distance of the Virgo ($\sim$17 Mpc) or Fornax ($\sim$18 Mpc) clusters. This ambitious goal requires an Extremely Large Telescope (ELT), with a diameter of 50–150m, operating in the optical/near-IR at its diffraction limit.

The extremely large telescopes (ELTs) are built at huge financial cost and usually involve partnership among several bodies/nations. Consequently and naturally, telescope time allocations in many, if not most, of such telescopes are based either directly or indirectly on the monetary contributions of the partners. This paper examines the economy, sociology, science and politics of the ELTs and their implications for the astronomers and/or astronomy in poorer developing nations.

This report is a general introduction on Chinese large telescope projects. It includes the ongoing project Large Sky Area Multi-Object Fiber Spectroscopic Telescope (LAMOST), and three projects which have reviewed by Chinese government recently: Five-hundred-meter Aperture Spherical (radio) Telescope (FAST); Space Solar Telescope (SST); Hard X-ray Modulation Telescope (HXMT). These three projects have finished their feasibility studies and development of key technologies. They are very likely to be approved by the Chinese government in 2006. Besides these large telescope projects, the site survey in Western China for large telescopes in optical, infrared, sub-millimeter and millimeter astronomy, the preliminary study on Chinese future giant optical/infrared telescopes, and a future extremely large wide field telescope are also briefly introduced.

Black hole (BH) theories predict the existence of an “intermediate” mass BH at the centers of dwarf elliptical (dE) galaxies. These intermediate mass black holes (IMBHs) are believed to bridge the observational gap between stellar-mass BHs ($M_{\rm BH} \lesssim 10^3{\rm M_\odot}$) and supermassive BHs ($M_{\rm BH} \gae 10^6{\rm M_\odot}$). Our project aims at finding tighter empirical constrains on the existence, location, and mass range of these hypothetical objects. For this purpose, we are conducting a deep IMBH search in a sample of $\sim$30 Local Volume dwarf galaxies. Using the Robert Stobie Spectograph (RSS) on the newly constructed Southern African Large Telescope (SALT), long-slit spectroscopic observations along the major-axis will be acquired for each galaxy to determine their kinematic and dynamical properties, particularly at their centers.

This paper presents the final discussion of the meeting, following introductory remarks by A. Ardeberg, B. Ellerbroek and C. Cunningham.

Areas surveyed for ELT projects using satellite data are described. A synopsis of the methodology used is given and selected results from recent studies are presented.

A tiny fraction (<1%) of very metal-deficient (12+log(O/H)≤7.6) blue compact dwarf (BCD) galaxies exhibits a nearly galaxy-wide starburst activity and no signatures of an old stellar host galaxy. The evolutionary status and formation history of these most metal-deficient BCDs are still a subject of debate. Various lines of evidence suggest, however, that these systems do not contain a substantial population of stars older than $\sim$1 Gyr and hence qualify as nearby young-galaxy candidates. Elaborated multiwavelength studies of these rare, most metal-deficient BCDs may therefore provide crucial insights into the formation and starburst-driven evolution of low-mass galaxies in the early universe.

ELTs will bring galaxies within 5 Mpc or more “as close as the Magellanic Clouds”. This is why stellar populations is such an exciting subject for ELTs. We can resolve galaxies into stars and learn their history (1) from the “fossil record” of old stars and (2) looking back in time. The confrontation of these two views will bring important new insights in the star formation history of galaxies and stellar evolution, at the same time.

IAU Symposium 232 allows a snapshot of ELTs at a stage when design work in several critical mass projects has been seriously underway for two to three years. The status and some of the main initial design choices are reviewed for the North American Giant Magellan Telescope (GMT) and the Thirty Meter Telescope (TMT) projects and the European Euro-50 and the Overwhelmingly Large (OWL) projects. All the projects are drawing from the same “basket” of science requirements, although each project has somewhat different ambitions. The role of the project offices in creating the balance between project scope, timeline and cost, the “iron triangle” of project management, is emphasized with the OWL project providing a striking demonstration at this meeting. There is a reasonable case that the very broad range of science would be most efficiently undertaken on several complementary telescopes.

A forthcoming step in the study of extrasolar planetary systems is the direct detection and characterization of Earth-like planets. An asset of the ELTs in that context is their very high angular resolution and their collecting area. The luminosity ratio between a terrestrial planet and its star ($10^{-10}$) is such an ambitious goal that a thorough study needs to be carried out. We started with a simple analysis of the fundamental limitations for the detection of extraterrestrial planets with ELTs. Here, we considered an extreme adaptive optics device upstream of a perfect coronagraph. Even with high Strehl ratios, the coronagraphic halo level is only $10^{-6}$ to $10^{-7}$ at typical exo-Earth angular distances. A calibration device is therefore mandatory to reach the contrast between a terrestrial planet and its star in the near infra-red. We considered a simple but realistic model taking into account dynamic aberrations left uncorrected by the adaptive optics system, static aberrations of optical system and differential static aberrations due to the calibration channel itself. Numerical simulations prove that, after the calibration, the limitations are set by the static aberrations which cannot be neglected anymore.

Adaptive Optics (AO) will be essential for accomplishing many, if not most, of the science objectives currently planned for Extremely Large Telescopes including GMT, OWL, and TMT. AO will be needed to support a range of instrumentation, including near infrared (IR) imagers and spectrometers, mid IR imagers and spectrometers, “planet finding” instrumentation and wide-field optical spectrographs. Multiple advanced AO systems, utilizing the full range of concepts currently under development, will need to be combined into an integrated architecture to meet a broad range of requirements for field-of-view, spatial resolution and spectral bandpass.

In this paper, we describe several of the possible options for these systems and outline the range of issues, trade studies and component development activities which must be addressed. Some of these challenges include very high-order, large-stroke wavefront correction, tip-tilt sensing with faint natural guide stars to maximize sky coverage, laser guide star wavefront sensing on a very large aperture and achieving extremely high contrast ratios for the detection of extra-solar planet and other faint companions of nearby bright stars.

We show that contrary to what is expected from 1D stationary model atmospheres, 3D hydrodynamical modeling predicts a considerable influence of convection on the spectral properties of late-type giants. This is due to the fact that convection overshoots into the formally stable outer atmospheric layers producing a notable granulation pattern in the 3D hydrodynamical models, which has a direct influence on the observable spectra and colors. Within the framework of standard 1D model atmospheres the average thermal stratification of the 3D hydro model can not be reproduced with any reasonable choice of the mixing length parameter and formulation of the turbulent pressure. The differences in individual photometric colors – in terms of 3D versus 1D – reach up to $\sim0.2$ mag, or $\Delta T_{\rm eff}\sim70$ K. We discuss the impact of full 3D hydrodynamical models on the interpretation of observable properties of late-type giants, briefly mentioning problems and challenges which need to be solved for bringing these models to a routine use within the astronomical community in 5–10 years from now.