MAORY, the Multi-conjugated Adaptive Optics RelaY for the European Extremely Large Telescope, will be located on one of the Nasmyth platforms of the telescope to provide multi conjugated adaptive optics correction of the wavefront. The scientific instruments fed by the module will benefit from a corrected field of view of 2 arcmin diameter with high performance uniformity across the field. The two post-focal deformable mirrors are projected at high altitude by the optical system based on 5 mirrors and one dichroic which splits the laser light of the artificial reference stars from the science channel. The third deformable mirror, conjugated to the ground, is integrated into the telescope. Six laser guide stars are foreseen in order to measure the wavefront distortions and three natural guide stars are used to solve the tip-tilt indetermination problem. The natural guide stars wavefront sensors are located close to the output focal plane in order to minimize the non common path aberrations. Two output ports are foreseen: one gravity invariant located below the optical bench and one on one side of the bench to feed large instruments placed on the Nasmyth platform.

The Multi-conjugate Adaptive Optics RelaY (MAORY) for the European Extremely Large Telescope (E-ELT) provides a corrected field of view of up to 2 arcmin diameter over the wavelength range 0.8-2.4 μm. It is expected to achieve a correction of high quality and uniformity with high sky coverage: with a seeing of 0.8 arcsec in the visible, the expected Strehl Ratio averaged over a 1 arcmin field is approximately 50% at 2.16 μm wavelength over 50% of the sky at the Galactic Pole. Wavefront correction is obtained by means of the E-ELT adaptive mirrors M4/M5 and of two post-focal deformable mirrors conjugated at 4km and 12.7km from the telescope pupil. Wavefront sensing is performed by 6 Sodium laser guide stars and by 3 natural guide stars, used to measure atmospheric and windshake tilt and to provide a reference for the focus and for the low-order aberrations induced by the Sodium layer. MAORY is located on the E-ELT Nasmyth platform and has a gravity invariant port, feeding the high angular resolution camera MICADO, and a lateral port for a detached instrument as the infrared spectrograph SIMPLE.

The Multi conjugate Adaptive Optics RelaY (MAORY) for the European Extremely Large Telescope is designed to compensate the effects of the atmospheric turbulence over a 2 arcmin field of view in the wavelength range 0.8-2.4 micron. The wavefront correction is performed by three deformable mirrors driven by a wavefront sensing system based on laser and natural guide stars. Accurate relative photometry and astrometry and infrared spectroscopy are the key science applications of the adaptive optics module with its client instruments.

We confirm an eighth gravitational lens system in the CAmbridge Sloan Survey Of Wide ARcs in the skY (CASSOWARY) catalogue. Exploratory observations with the X-shooter spectrograph on the Very Large Telescope of the European Southern Observatory show the system CASSOWARY 5 (CSWA 5) to consist of at least three images of a blue star-forming galaxy at z = 1.0686, lensed by an apparent foreground group of red galaxies, one of which is at z = 0.3877. The lensed galaxy exhibits a rich spectrum with broad interstellar absorption lines and a wealth of nebular emission lines. Preliminary analysis of these features shows the galaxy to be young, with an age of similar to 25-50 Myr. With a star formation rate of similar to 20 M-circle dot yr-1, the galaxy has already assembled a stellar mass M-* similar to 3 x 109 M-circle dot and reached half-solar metallicity. Its blue spectral energy distribution and Balmer line ratios suggest negligible internal dust extinction. A more in-depth analysis of the properties of this system is currently hampered by the lack of a viable lensing model. However, it is already clear that CSWA 5 shares many of its physical characteristics with the general population of UV-selected galaxies at redshifts z = 1-3, motivating further study of both the source and the foreground mass concentration responsible for the gravitational lensing.

We have used spectra obtained with X-shooter, the triple arm optical-infrared spectrograph recently commissioned on the Very Large Telescope of the European Southern Observatory, to confirm the gravitational lens nature of the CAmbridge Sloan Survey Of Wide ARcs in the skY (CASSOWARY) candidate CSWA 20. This system consists of a luminous red galaxy at redshift z(abs) = 0.741, with a very high velocity dispersion, sigma(lens) similar or equal to 500 km s(-1), which lenses a blue star-forming galaxy at z(em) = 1.433 into four images with a mean separation of similar to 6 arcsec. The source shares many of its properties with those of UV-selected galaxies at z = 2-3: it is forming stars at a rate SFR similar or equal to 25 M-circle dot yr(-1), has a metallicity of similar to 1/4 solar and shows nebular emission from two components separated by 0.4 arcsec (in the image plane), possibly indicating a merger. It appears that foreground interstellar material within the galaxy has been evacuated from the sightline along which we observe the starburst, giving an unextinguished view of its stars and H II regions. CSWA 20, with its massive lensing galaxy producing a high magnification of an intrinsically luminous background galaxy, is a promising target for future studies at a variety of wavelengths.

MAORY is the Multi-conjugate Adaptive Optics RelaY module for the European Extremely Large Telescope. It will be located on the Nasmyth platform of the telescope to feed scientific instruments. The module is supposed to re-image one to one the telescope focal plane with diffraction limited optical quality and to provide multi-conjugate adaptive optics correction of the wavefront distortion induced by the atmosphere. The system is based on six laser guide stars for sensing the wavefront distortion and three deformable mirrors for correcting it. A dichroic is used to split the laser light from the light of the scientific and natural guide stars channel. Two output ports, selected by the dichroic orientation, are foreseen: one in a gravity invariant configuration and one in a vertical position to feed large instruments. In this article the current optical and mechanical design are presented together with the thermal analysis.

MAORY is the multi-conjugate adaptive optics module for the European Extremely Large Telescope. A conceptual design study is in progress and is approaching the final review. A description of the current design and of the expected performance is presented.

The European Extremely Large Telescope (E-ELT) project is very much based on the heritage of the ESO Very Large Telescope, the array of four 8 m optical telescopes located on the Paranal peak in the Atacama desert. The VLT started operation in 1998 and with its complement of 11 instruments permanently on line has proved to be the most powerful facility for ground-based astronomy at optical and infrared wavelengths (see the contribution by A. Moorwood in these Proceedings). In the case of the VLT, an Instrumentation Plan Proposal was distributed to the community as early as 1989 and this approach, with corrections and upgrades introduced on the way, has been very effective in developing a coherent set of instruments in collaboration between ESO, Universities and Institutes in the ESO member countries. In the case of the E-ELT, ESO is now coordinating a series of instrument studies with the goal to define a first generation of instruments to be included in the proposal for construction due at the beginning of 2010.

X-shooter is a wide band (U to K) intermediate resolution (4000-14000) single object three-arms spectrograph for the VLT. Currently in the last phase of integration, X-shooter will see the first light at ESO Paranal as the first of the VLT second generation instruments in the last quarter of 2008. We describe in this paper the final steps in the integration and testing phase of the central Backbone with its key functions (including the active flexure compensation mirrors) and of the two UV-Blue and Visible spectroscopic arms. We report on the stability results of the preslit optics and of the spectrographs and on the remarkable efficiency which is derived from the measurements of the optical components of the instrument.

The multi-conjugate adaptive optics module for the European Extremely Large Telescope has to provide a corrected field of medium to large size (up to 2 arcmin), over the baseline wavelength range 0.8-2.4 μm. The current design is characterized by two post-focal deformable mirrors, that complement the correction provided by the adaptive telescope; the wavefront sensing is performed by means of a high-order multiple laser guide star wavefront sensor and by a loworder natural guide star wavefront sensor. The present status of a two years study for the advanced conceptual design of this module is reported.

A European ELT in the 30–60m diameter class is currently being studied by ESO in collaboration with the astronomical community. Two designs are under consideration in this phase, to be concluded by the end of 2006. The baseline is a 42m, 5 mirror telescope, fall back is a Gregorian Design like in the American 30m TMT proposal. Both designs include an adaptive mirror in the optical train. The gain expected from an ELT with respect to the current generation of 8–10 m telescopes are most significant for the programs which require high angular resolution or are photon-starved. Concept studies have been carried out for 1st generation instruments. They include high resolution spectrographs for the visual and the infrared and a medium resolution, multiobject spectrograph for the NIR.

A direct measurement of the universe's expansion history could be made by observing in real time the evolution of the cosmological redshift of distant objects. However, this would require measurements of Doppler velocity drifts of ∼1 centimeter per second per year, and astronomical spectrographs have not yet been calibrated to this tolerance. We demonstrated the first use of a laser frequency comb for wavelength calibration of an astronomical telescope. Even with a simple analysis, absolute calibration is achieved with an equivalent Doppler precision of ∼9 meters per second at ∼1.5 micrometers—beyond state-of-the-art accuracy. We show that tracking complex, time-varying systematic effects in the spectrograph and detector system is a particular advantage of laser frequency comb calibration. This technique promises an effective means for modeling and removal of such systematic effects to the accuracy required by future experiments to see direct evidence of the universe's putative acceleration.

New results from the search for H2 absorption in the damped Lyα galaxy at redshift z = 3.4 toward QSO 0000–2620 (zem = 4.1) are reported. The high-resolution (λ/∆λ = 48, 000) spectra of Q0000–2620 were obtained using the Ultraviolet Visual Echelle Spectrograph (UVES) on the 8.2m ESO Kueyen telescope. The ortho-H2 column density is found to be N(J = 1) = (5.55±1.35)×10 13 cm (2σ C.L.). The combination ofN(J = 1) with the limits available for other low rotational levels restricts the excitation temperature Tex in the range (290−540) K. This gives the total H2 column density of N(H2) = (8.75 ± 1.25) × 10 13 cm and the corresponding fraction of hydrogen atoms bound in molecules of f(H2) = (6.8± 2.0) × 10.

Precise radial velocity measurements (delta v/c ~ 10^{-7}) of FeII lines in damped Ly-alpha systems from very high quality VLT/UVES spectra of quasars HE0515-4414 and Q1101-264 are used to probe cosmological time dependence of the fine structure constant, alpha. It is found that between two redshifts z1 = 1.15 and z2 = 1.84 the value of Delta alpha/alpha changes at the level of a few ppm: (alpha_z2 - alpha_z1)/alpha_0 = 5.43 +/- 2.52 ppm. Variations of alpha can be considered as one of the most reliable method to constrain the dark energy equation of state and improvements on the accuracy of the wavelength calibration of QSO spectra are of great importance.

The European Southern Observatory (ESO) is conducting a phase B study of a European Extremely Large Telescope (E-ELT). The baseline concept foresees a 42m primary, 5 mirror adaptive telescope with two of the mirrors giving the possibility of very fast correction of the atmospheric turbulence. In parallel to the telescope study, ESO is coordinating 8 studies of instruments and 2 of post-focus Adaptive Optics systems, carried out in collaboration with Institutes in the member states. Scope of the studies, to be completed by 1Q 2010, is to demonstrate that the high priority scientific goals of the E-ELT project can be achieved with feasible and affordable instruments. The main observing modes being considered are: NIR wide field imaging and spectroscopy to the diffraction limit or with partial correction of the atmospheric seeing; high spectral resolution, high stability visible spectroscopy; high contrast, diffraction limited imaging and spectroscopy; DL mid-infrared imaging and spectroscopy. The status of the 8 current studies is presented.

X-shooter consists of a central structure (backbone) which supports three prismcross-dispersed echelle spectrographs optimised for the UV-Blue, Visible and Near-IR wavelength ranges respectively. The backbone contains the calibration and acquisition units, an IFU that can be inserted in the light path, two dichroics to split the beam among the three arms, and relay optics to feed the entrance slits of the three spectrographs. A functional diagram summarising all the functions of X-shooter is shown in Figure 1; the main instrument parameters are listed in Table 1.

An accurate method to measure the abundance of high-redshift galaxies consists in the observation of absorbers along the line of sight toward a background quasar. Here, we present abundance measurements of 13 z>3 sub-Damped Lyman-alpha Systems (quasar absorbers with HI column density 19 < log N(HI) < 20.3 cm^-2) based on the high resolution observations with VLT UVES spectrograph. These observations more than double the metallicity information for sub-DLAs previously available at z>3. This new data, combined with other sub-DLA measurements from the literature, confirm the stronger metallicity redshift evolution than for the classical Damped Lyman-alpha absorbers. Besides, these observations are used to compute for the first time the fraction of gas ionised from photo-ionisation modelling in a sample of sub-DLAs. Based on these results, we calculate that sub-DLAs contribute no more than 6% of the expected amount of metals at z~2.5. We therefore conclude that even if sub-DLAs are found to be more metal-rich than classical DLAs, they are insufficient to close the so-called ``missing metals problem''.

X-shooter is a second generation VLT instrument currently under construction by a Consortium of Institutes from Denmark, Italy, The Netherlands, France and ESO. X-shooter is designed to acquire intermediate (5000-10000) resolution spectra of single objects in an unprecedented wide wavelength coverage (320-2500 nm). In order to maximize efficiency the beam is divided into 3 arms (UV, VIS and NIR) by a system of dichroics. X-shooter is designed for the Cassegrain focus of one VLT unit. The mechanical assembly has to provide specific solutions to maintain 3 arms within the strict tolerances required by the intermediate resolution, during the typical motions of the Cassegrain focal station. It must as well ensure the permanent co-alignment of the 3 slits and the stability of the spectral format on the focal plane of each arm, allowing long intervals between calibration exposures. The above requirements have been met via an innovative mechanical design merging passive stiffness and active control to obtain a light, accessible and functional assembly. This paper gives a description of the X-shooter mechanical assembly with main emphasis on the common "backbone" structure and the UV- and VIS spectrograph arms.