The ongoing conceptual design activities for the Thirty Meter Telescope (TMT) illustrate many (if not virtually all) of the advanced instrumentation technologies under consideration for future extremely large telescopes. First light capabilities must be based upon credible extrapolations of existing systems and components, while potential upgrades and follow-on systems should explore the full range of advanced and innovative technologies currently proposed for scientific instrumentation and adaptive optics (AO). An affordable technology development program must then be implemented which balances these conflicting objectives.

In this paper, we outline the range of innovative AO component technologies now under discussion for TMT, and describe some of the contracts and studies comprising our AO development program. Components that require advances include piezostack and MEMS deformable mirrors; adaptive secondary mirrors; fast, low noise detectors for both laser- and natural guide star wavefront sensing; guidestar laser sources; and processing electronics for the implementation of AO control algorithms. Instrumentation studies are also underway that investigate issues related to the huge size of seeing-limited instruments; large gratings; integral field spectroscopy; detectors; and advanced techniques for sky subtraction.

A detailed abundance analysis of four giants in the metal-rich bulge globular cluster NGC 6553 is carried out, based on optical high resolution échelle spectra obtained with UVES at the ESO VLT-UT2 Kueyen telescope. A mean radial heliocentric velocity of −1.86 km s−1 is found. Stellar parameters are derived from spectroscopic data based on Fe I and Fe II lines. Enhanced abundance ratios for the α-elements Mg and Si with respect to Ca and Ti are obtained. The odd-Z elements are typically solar. A solar value for the r-process element Eu ([Eu/Fe] = +0.05 ±0.06) was also found.

Globular clusters (GCs) and nuclei in dEs are important probes for for studying cosmology and galaxy evolution. GCs and nuclei are usually formed in the high pressures of starbursts, therefore resolved stellar color-magnitude diagrams and integrated colors, magnitudes, or spectra yield ages and metallicities which are snapshots of the conditions during the most violent and important star forming episodes of the galaxies. Most are older, more metal-poor, and more enriched in $\alpha$-elements than the underlying dE field stars. About 25% have formed within the last $\sim$6~Gyr from enriched gas. Many nuclei have the properties of brights GCs but some can be distinguished by large sizes and composite stellar populations. The relatively large numbers of GCs in dEs shows that they are an important source of GCs to galaxies that accrete them.

We suggest that the ultraluminous X-ray sources located in external galaxies (ULXs) are supercritical accretion disks like that in SS433, observed close to the disk axis. We estimate parameters of the SS433 funnel, where the relativistic jets are formed. Emergent X-ray spectrum in the proposed model of the multicolor funnel (MCF) is calculated. The spectrum can be compared with those of ULXs. We predict a complex absorption-line spectrum with broad and shallow K$\alpha$/Kc blends of the most abundant heavy elements and particular temporal variability. Another critical idea comes from observations of nebulae around the ULXs. We present results of 3D-spectroscopy of nebulae of two ULXs located in Holmberg II and NGC6946. In both cases the nebula is found to be powered by the central black hole. The nebulae are compared with SS433 nebula (W50).

SAO has set up a testbed to study coronagraphic techniques, starting with Labeyrie's multi-step speckle reduction technique. This technique expands the general concept of a coronagraph by incorporating a speckle corrector (phase and/or amplitude) in combination with a second occulter for speckle light suppression. The correction function is derived applying the phase diversity method on images taken in focus and slightly out-of-focus. The occulter masks for the testbed will initially be produced lithographically. However, in a parallel program we are studying a new manufacturing method. This method utilizes focussed ion beams and will directly mill the mask shape into absorbing material deposited on a transparent substrate.

Significant progress has been made in the last decade toward an understanding of the intergalactic He II absorption. At redshifts $z<2.8$, individual absorbers are found to be ionised mainly by a hard quasar continuum, but their ionisation states vary considerably and the ionising radiation field may have contributions from a soft stellar continuum. The He II opacity increases significantly at $z\sim 2.8$, suggesting a possible end of the general reionisation of intergalactic He II. Using the massive SDSS database and UV selection with HST and GALEX, we have found new quasars at $z>3.5$, with detected He II absorption. Future observations will pinpoint the epoch of reionisation of the intergalactic He II.

In this paper, the new coronagraph that will be mounted at the Pic du Midi Observatory (IMCCE - T1m telescope) is presented. To optimize the occulting process of a Lyot coronagraph, a compressed mercury (Hg) drop is used as an occulting disk and its size control offers an adaptation to the seeing conditions or to the Airy diameter fraction needed. In addition to the Hg-mask, a variation on the theme is proposed by a diameter and wavelength adaptive phase mask made of a gas bubble in immersion oil between two optical windows. The instrument concept offers a good versatility to test other mask type and pupil apodization techniques.

I summarise the ELT requirements derived from the science cases in the area of galaxy formation/evolution and cosmology. This summary is based on the talks, posters and discussion in parallel Session A of this meeting, but also makes use of various publically-available ELT science case documents. Topics covered include studies of black holes, dark matter, properties of galaxies at a range of redshifts (including the first galaxies to form), fundamental constants and cosmology.

Our understanding on the nitrogen origin has recently greatly changed. New data on nitrogen abundances in very metal-poor stars ($-4<[Fe/H]<-3$) show a quite surprising result: a high N/O ratio suggestive of high levels of production of primary nitrogen in massive stars. Moreover, none of the stars measured so far has N/O ratios as low as the ones observed in Damped Lyman-α systems (DLAs) (currently the systems showing the lowest N/O ratios in the universe). We studied the implications of the above new data set for our understanding on the nitrogen enrichment in the Milky Way. We find that, to explain the new observations, we need to adopt stellar yields computed with stellar models in which rotation is taken into account and assume that stars born at Z <10−5 contribute a lot more N than the most recent calculations available in the literature for Z= 10−5. The implications of our findings for our understanding of the nature of Damped Lyman-α systems (DLAs) are also briefly discussed.

We present a new technique to determine age and metallicity of old stellar populations (globular clusters and elliptical galaxies) using an iterative principal component analysis on narrow band (Strömgren) colors. Our technique is capable of reproducing globular cluster [Fe/H] values to 0.02 dex and CMD ages to 1.0 Gyrs. We also present preliminary results on the application of our technique to a sample of high mass, field ellipticals and low mass, cluster dwarf ellipticals. We confirm the results of earlier studies which find that globular clusters increase in metallicity with age and that age and metallicity increase with galaxy mass. However, we find that dwarf ellipticals deviate from the elliptical sequence by having little to no correlation between age and metallicity.

Chandra and XMM-Newton improve our understanding of X-ray populations in galaxies. In particular, there exists a class of ultra-luminous X-ray sources (ULXs) for which the observed luminosity is greater than $10^{39}$ ergs s$^{-1}$. ULXs are of great interest since they represent a population of possible intermediate-mass black holes. While the spectra of majority of ULXs are similar to Galactic X-ray binaries, a few ULXs have very soft X-ray emission ($kT=50$–100 eV) resembling supersoft X-ray sources (SSSs) discovered in the Milky Way and the Magellanic Clouds. We here report some recent multiwavelength observations of three ultra-luminous SSSs in M101, NGC 300, and the Antennae. They have shown many interesting behaviors such as state transitions, spectral changes, and time variabilities in different timescales. Unlike typical SSSs, ultra-luminous SSSs are unlikely associated with white dwarfs because of the high X-ray luminosities. We discuss some binary models involving stellar-mass and intermediate-mass black holes to explain the nature of the systems.

Nine 20$\,M_\odot$ models were computed with metallicities ranging from solar, through $Z=10^{-5}$ ([Fe/H]∼−3.1) down to $Z=10^{-8}$ ([Fe/H]∼−6.1) and with initial rotational velocities between 0 and 600 km s−1 to study the impact of initial metallicity and rotational velocity (Hirschi (2005)). The very large amounts of 14N observed (∼0.03 M[odot ]) are only produced at $Z=10^{-8}$ (PopII 1/2). The strong dependence of the 14N yields on rotation and other parameters like the initial mass and metallicity may explain the large scatter in the observations of 14N abundance. The metallicity trends are best reproduced by the models with $\upsilon_{ini}/\upsilon_c \sim 0.75$, which is slightly above the mean observed value for OB solar metallicity stars. Indeed, in the model with $\upsilon_{ini}$ = 600 km s−1 at $Z=10^{-8}$, the 16O yield is reduced due to strong mixing. This allows in particular to reproduce the upturn for C/O and a slightly decreasing [C/Fe], which are observed below [Fe/H]∼−3.

We recently reported the discovery of a new galaxy type, ultra-compact dwarf (UCD) galaxies, in both the Fornax and Virgo clusters. Here we present new detections of a larger population of UCDs in the Fornax Cluster, as well as the first detections of UCDs in two galaxy groups. We extended our original survey of the Fornax Cluster 1 magnitude fainter, finding a further 46 new compact objects. This means that UCDs outnumber normal galaxies in the central region of the Fornax Cluster. We used this large UCD sample to test the tidal stripping model: simulations indicate that only about half of the UCD population may have formed by disruption of the observed population of nucleated dwarf galaxies. As the UCDs are strongly clustered towards the cluster centre, we conclude that the remaining UCDs must be associated with the much earlier assembly of the central galaxy.

In a subset of the most luminous of the so-called “ultra-luminous” X-ray sources in nearby galaxies, there is evidence for black holes with masses considerably higher than found in Galactic binaries. Apart from extremely high X-ray luminosities, cool disks found in the X-ray spectra of these sources and X-ray timing measurements form the basis for present evidence for intermediate-mass black holes in these sources. New optical and radio measurements appear to support the X-ray evidence. I will review recent X-ray, optical, and radio observations of these ULXs, and discuss the strengths of the intermediate-mass black hole interpretation, arguments against this interpretation, and future prospects for revealing the nature of these ULXS more clearly.

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.

SPICA is a cooled, single large-mirror space-telescope, which is under discussion as an succsesor of the ASTRO-F mission. One of the most ambitious challenges of the SPICA mission is the direct observations of exoplanets with a coronagraph instrument. We report cryogenic infrared optics to realize high quality wavefronts for the SPICA coronagraph.

The SPICA satellite will be launched by an H-IIA rocket to Sun-Earth L2 Halo orbit early in the 2010s. The SPICA telescope is a Ritchey-Chretien optics with 3.5m diameter primary mirror, and cooled down to 4.5 K in orbit by radiation cooling and mechanical cryo-coolers. Main working wavelengths are 5–200 micron. Advantages of the SPICA coronagraph are the infrared wavelenths where the contrast between planets and central stars are smaller than the optical wavelengths, and that the cooled space telescope consists of monolithic mirrors.

Development of light-weight cooled telescope is one of the most important tasks to realize SPICA. At the present, sintered SiC and carbon fiber reinforced SiC (C/SiC) composite are candidate materials for the mirrors, truss, and optical bench. For these materials, estimations and improvements of basic property and surface roughness in cryogenic temperatures have been carried out. Deformation of trial product mirrors by cooling is also examined.

We are developing cryogenic deformable mirrors (DMs) because wave front accuracy of the SPICA telescope is 0.35 micron RMS, which is not enough for our coronagraphic instrument. For MEMS (Micro Electro Mechanical System) DM and some others, measurements of thermal deformation by cooling, electrical response, and heat generation are undergoing. Developments of a tip-tilt system for cryogenic usage started to cancel vibration caused by the cryo-coolers and other components and to realize a diffraction limit resolution. The first result of our binary mask coronagraph experiment is also shown.

The central controversy over whether or not ultraluminous X-ray sources (ULXs) contain a new “intermediate-mass” class of black holes (IMBHs) remains essentially unresolved. Indeed, whilst many recent X-ray spectroscopy results find evidence for a cool (100–200 eV) accretion disc – the expected signature of a ${\sim} 1000$ M$_{\odot}$ IMBH – in ULX spectra, most of the circumstantial evidence (a combination of multiwavelength counterparts, theoretical modelling and the behaviour of accreting black holes in our own Galaxy) argues that the black holes underlying ULXs could be substantially less massive. I will present a new analysis of the deepest XMM-Newton observations of ULXs that directly addresses their underlying nature. This includes the results of a new 100-ks observation of the archetypal ULX Holmberg II X-1. Though a slight soft excess in its X-ray spectrum can be fitted by a cool accretion disc model, a rigorous analysis of the temporal data shows that the black hole cannot be larger than ${\sim}100$ M$_{\odot}$. Interestingly, we find evidence that the putative accretion disc corona is cool and optically thick in this source, unlike most Galactic binaries. We have also undertaken a detailed spectral analysis of the next 12 best ULX datasets in the XMM-Newton archive. Using physically self-consistent spectral modelling we show that whilst all the ULXs show possible cool accretion discs, the majority of these ULXs appear dominated by an optically-thick Comptonising medium. I will argue that this is evidence that most (though not necessarily all) ULXs contain black holes that are at most a few tens of solar masses in size.

The abundance distributions of cluster and field halo populations will be considered. Abundance data for most elements of the Periodic Table are much sparser for globular clusters than for individual halo field stars, mainly due to the relative lack of high resolution spectra in the blue for the former group. But the available data do suggest that, in spite of remaining uncertainties in the observational data, that chemical composition differences in the heavier elements (Fe-peak and beyond) are small, indicating common nucleosynthetic origins for all halo populations.

We review some properties of ultra compact dwarf galaxies (UCDs) in Fornax and of their brighter counterparts in Abell 1689, among which are two M32 twins, and discuss various possible UCD formation scenarios. We note that it is indispensable to carefully take into account the bright end of the globular cluster luminosity function when estimating the number density of UCDs. It is suggested that the search for more luminous UCDs in dense and rich galaxy clusters is the best way towards establishing UCDs as a new class of galaxies.

We summarise the science cases for an ELT that were presented in the parallel session on the intergalactic medium, and the open discussion that followed the formal presentations. Observations of the IGM with an ELT provides tremendous potential for dramatic improvements in current programmes in a very wide variety of subjects. These range from fundamental physics (expansion of the Universe, nature of the dark matter, variation of physical constants), cosmology (geometry of the Universe, large-scale structure), reionisation (ionisation state of the IGM at high $z\ge 6$), to more traditional astronomy, such as the interactions between galaxies and the IGM (metal enrichment, galactic winds and other forms of feedback), and the study of the interstellar medium in high $z$ galaxies through molecules. The requirements on ELTs and their instruments for fulfilling this potential are discussed.