Vincenzo De Caprio

ESPRESSO: the Echelle spectrograph for rocky exoplanets and stable spectroscopic observations

ESPRESSO, the Echelle SPectrograph for Rocky Exoplanets and Stable Spectroscopic Observations, will combine the efficiency of modern echelle spectrograph design with extreme radial-velocity precision. It will be installed on ESOs VLT in order to achieve a gain of two magnitudes with respect to its predecessor HARPS, and the instrumental radialvelocity precision will be improved to reach cm/s level. Thanks to its characteristics and the ability of combining incoherently the light of 4 large telescopes, ESPRESSO will offer new possibilities in various fields of astronomy. The main scientific objectives will be the search and characterization of rocky exoplanets in the habitable zone of quiet, nearby G to M-dwarfs, and the analysis of the variability of fundamental physical constants. We will present the ambitious scientific objectives, the capabilities of ESPRESSO, and the technical solutions of this challenging project.

The International Robotic Antarctic Infrared Telescope (IRAIT)

Thanks to exceptional coldness, low sky brightness and low content of water vapour of the above atmosphere Dome C, one of the three highest peaks of the large Antarctic plateau, is likely to be the best site on Earth for thermal infrared observations (2.3-300 μm) as well as for the far infrared range (30 μm-1mm). IRAIT (International Robotic Antarctic Infrared Telescope) will be the first European Infrared telescope operating at Dome C. It will be delivered to Antarctica at the end of 2006, will reach Dome C at the end of 2007 and the first winter-over operation will start in spring 2008. IRAIT will offer a unique opportunity for astronomers to test and verify the astronomical quality of the site and it will be a useful test-instrument for a new generation of Antarctic telescopes and focal plane instrumentations. We give here a general overview of the project and of the logistics and transportation options adopted to facilitate the installation of IRAIT at Dome C. We summarize the results of the electrical, electronics and networking tests and of the sky polarization measurements carried out at Dome C during the 2005-2006 summer-campaign. We also present the 25 cm optical telescope (small-IRAIT project) that will installed at Dome C during the Antarctic summer 2006-2007 and that will start observations during the 2007 Antarctic winter when a member of the IRAIT collaboration will join the Italian-French Dome C winter-over team.

Preparing for the phase B of the E-ELT MCAO module project

The Multi-Conjugate Adaptive Optics module for the European Extremely Large Telescope has been designed to achieve uniform compensation of the atmospheric turbulence effects on a wide field of view in the near infrared. The design realized in the Phase A of the project is undergoing major revision in order to define a robust baseline in view of the next phases of the project. An overview of the on-going activities is presented.

The camera of the ASTRI SST-2M prototype for the Cherenkov Telescope Array

In the context of the Cherenkov Telescope Array observatory project, the ASTRI SST-2M end-to-end prototype telescope, entirely supported by the Italian National Institute of Astrophysics, is designed to detect cosmic primary gamma ray energies from few TeV up to hundreds of TeV. The ASTRI SST-2M prototype camera is part of the challenging synergy of novel optical design, camera sensors, front-end electronics and telescope structure design. The camera is devoted to imaging and recording the Cherenkov images of air showers induced by primary particles into the Earth’s atmosphere. In order to match the energy range mentioned above, the camera must be able to trigger events within a few tens of nanoseconds with high detection efficiency. This is obtained by combining silicon photo-multiplier sensors and suitable front-end electronics. Due to the characteristic imprint of the Cherenkov image that is a function of the shower core distance, the signal dynamic range of the pixels and consequently of the front-end electronics must span three orders of magnitude (1:1000 photo-electrons). These and many other features of the ASTRI SST-2M prototype camera will be reported in this contribution together with a complete overview of the mechanical and thermodynamic camera system.

Numerical simulations of MAORY MCAO module for the ELT

MAO (MAORY Adaptive Optics) is the a developed numerical simulation tool for adaptive optics. It was created especially to simulate the performance of the MAORY MCAO module of the Extremely Large Telescope. It is a full end-to-end Monte-Carlo code able to perform different flavors of adaptive optics simulation. We used it to investigate the performance of a the MAORY and some specific issue related to calibration, acquisition and operation strategies. As, MAORY, MAO will implement Multi-conjugate Adaptive Optics combining Laser Guide Stars (LGS) and Natural Guide Stars (NGS) measurements. The implementation of the reference truth WFS completes the scheme. The simulation tool implements the various aspect of the MAORY in an end to end fashion. The code has been developed using IDL and use libraries in C++ and CUDA for efficiency improvements. Here we recall the code architecture, we describe the modeled instrument components and the control strategies implemented in the code.

DIORAMAS: a wide-field visible and near-infrared imaging multi-slit spectrograph for the EELT

We present the science, design and performances of DIORAMAS, an imager and multi-slit spectrograph for the European Extremely Large Telescope. It covers a wide 6.8x6.8 arcmin2 field, a large wavelength range 0.37 to 1.6 microns. The exceptional performances of this concept will enable extremely deep images to magnitudes AB~30 and high multiplex spectroscopy with up to ~500 slits observed simultaneously at spectral resolutions from R~300 to more than 120 slits at R~3000. The technical design is robust with only proven technology, and DIORAMAS could be developed on a timescale compatible with the EELT first light.

Euclid ENIS Spectrograph Focal Plane Design

The ENIS wide-field spectrograph is part of the instrument package on board of the European space mission Euclid devoted to map the dark universe and proposed for launch in 2017. ENIS will operate in the near-IR spectral region (0.8-2 μm) and will provide in 4-5 years an accurate and extremely large survey of cosmological redshifts. The instrument focal-plane is based on a combination of state of the art detectors light fed by a slitless spectrograph allowing coverage and analysis of a high number of targets per cycle. During the feasibility study a spectrograph option based on Digital Micromirror Device (DMD) programmable slits, allowing a significant increase in instrumental sensitivity and accuracy, has also been examined. ENIS has been recently (Feb this year) pre-selected for a phase-A study within a group of three medium class missions; final selection is foreseen for the end of next year after a new phase of instrument revision. A description of the work done during the feasibility-study phase for the ENIS focal-plane is here presented.

Path to the stars: the evolution of the species in the hunting to the GRBs

During the last years, a number of telescopes and instruments have been dedicated to the follow-up of GRBs: recent studies of the prompt emission (see for instance GRB080319B) and of their afterglows, evidenced a series of phenomena that do not fit very well within the standard fireball model. In those cases, optical observations were fundamental to distinguish among different emission mechanisms and models. In particular, simultaneous observation in various optical filters became essential to understand the physics, and we discovered the need to have a detailed high time resolution follow up. Finally, recent observations of the polarization in GRB 090102 clearly indicate the presence of an ordered magnetic field favoring the electromagnetic outflows models. This is, however, only one case and, in order to detail properly the model, we need a bit of statistics. But, after the Swift launch, the average observed intensity of GRB afterglows showed to be lower than thought before. Robotic telescopes, as demonstrated by REM, ROTSE, TAROT, etc. (but see also the GROND set up) is clearly the winning strategy. Indeed, as we will also briefly discuss later on, the understanding of the prompt emission mechanism depends on the observations covering the first few hundreds seconds since the beginning of the event with high temporal resolution. To tackle these problems and track down a realistic model, we started the conceptual design and phase A study of a 4 meter class, fast-pointing telescope (40 sec on target), equipped with multichannel imagers, from Visible to Near Infrared (Codevisir/Pathos). In the study we explored all the different parts of the project, from the telescope to the instrumental suite to data managing and analysis, to the dome and site issue. Contacts with industry have been fruitful in understanding the actual feasibility of building such a complex machine and no show stoppers have been identified, even if some critical points should be better addressed in the Phase B study. In this paper, we present the main results of the feasibility study we performed.

A Path to the Stars: The Evolution of the Species

During the last years, a number of telescopes have been dedicated to the followup of the GRBs. But after the Swift launch, the average observed intensity of the GRBs showed to be lower than thought before. Our experience with the robotic 60 cm REM telescope confirmed this evidence, with a large number of lost GRBs. Then, we proposed to study the feasibility of a 4 m fast pointing class telescope, equipped with a multichannel imagers, from Visible to Near Infrared. In this paper, we present the main result of the feasibility study we performed so far.

MAORY for ELT: preliminary mechanical design of the support structure

MAORY (Multi Conjugate Adaptive Optics RelaY) is one of the four instruments for the ELT (Extremely Large Telescope) approved for construction. It is an adaptive optics module able to compensate the wavefront disturbances affecting the scientific observations, achieving high strehl ratio and high sky coverage. MAORY will be located on the straight-through port of the telescope Nasmyth platform and shall re-image the telescope focal plane to a wide field camera (MICADO) and a possible future second instrument. A trade-off study among different mechanical design options for the main mechanical structure has been carried out. This paper outlines an overview of the mechanical design that gives a better result in terms of stability, vibrations and manufacturing.