A program for developing TES microcalorimeters for contributions to future Italian X-ray astronomy missions is under
course. Its main scientific goals are the spectroscopic study of extreme astrophysical objects, characterized by very large
energy release over short time scale, in particular gamma-ray bursts and transient compact objects, and the study of the
early and close-by Universe by using gamma-ray bursts as cosmological beacons. Presently, the energy resolution of our
detector has been improved to about 6 eV at 6 keV, with rise-time of about 10 μs and fall time of few hundreds of μs.
We are developing and studying the suitable absorbers for high count rate performances.
From a preliminary study on the project of a Large Antarctic Telescope for the Concordia Station at Dome C, two qualifying points seem important to be emphasized:
a) the first point is to think of a large diameter Telescope, able to achieve high angular resolution measures, in the sub-arcsec range in the mid-ir, that the science, especially that concerned with star forming phenomena, is strongly requiring, using in this way a sensitivity limit never reached before which is amplified by the exceptionality of the site exploited.
b) The second point, also related to the site, is to realize a non-conventional instrument with the highest degree of simplicity in the structure design, in the configurations, in the telescoped control and in the measuring modes, as to face the extreme conditions imposed by a space-like environment such as Dome C and also in order to cut costs.
Furthermore the idea is to assure the use of such an instrument at wavelengths higher than the mid-ir region, to which the telescope is principally devoted, thus expanding the interest of the astronomical community for Antarctic Astronomy. In the design phase the optimized configurations assuring the possibility to observe in the near-mid- and far-ir and in the sub-mm range, will be selected, obtaining the particular optimized structure by making some modifications that could be implemented in Antarctica during the summer season. Every configuration will permit to have the optimized conditions to observe at different wavelengths and for different types of measures (imaging; polarimetry; spectrscopy; large or small fields of view, etc.) giving priority in some cases to the highest angular resolution or to the highest sensitivity, or to largest field of view.
Some example will be given about technical solutions expected for the near and mid-ir in the light of the present and future possibilities in these domains.
The first results obtained from the Site Campaigns performed in the last years in different locations of the Antarctic Continent and the acquired experience obtained from the first astronomical IR measures with SPIREX, have in fact opened the way to a present time challenge, about the installation of a large IR Telescope in the best possible site on earth, that will be competitive with the present frontier of ground based and space telescopes in the Infrared range.
A project in this context has been submitted to the Italian Plan for Antarctic Research (PNRA), in collaboration with French and Australian colleagues that began to be funded this year. The project entitled “A preliminary study for a Large Infrared Telescope at Dome C”, will lay the bases for the realization of a non-conventional instrument for the mid-IR domain, suited for the very particular and severe Antarctic situation.
In this first paper a general overview is done about the future development plan for the GTA (Grande Telescopio Antartico), paying attention to the following themes:
Large aperture and low emissivity and high reliability of Antarctic IR telescopes
High resolution and very high sensitivity objectives for a mid-ir Survey Telescope.
Non-conventional observing modes for quasi drift-scan measurements.