IRAIT, robotic infrared telescope in Antarctica
J.Colomé1, C.Abia2, I.Domínguez2, J.Isern1,3, G.Tosti4, M.Busso4, O.Straniero5
1Institut
d’Estudis Espacials de Catalunya (IEEC), F. Ciències - Campus UAB, 08193 Bellaterra, Spain
2Dpto.Física Teórica y del Cosmos, Universidad de Granada, 18071 Granada, Spain
de Ciencias del Espacio (CSIC), Gran Capità 2-4 (Edifici Nexus), 08034 Barcelona, Spain
4Osservatorio Astronomico e Dipartimento di Fisica, Universitá di Perugia, via A. Pascoli, 06123 Perugia, Italy
5INAF-Osservatorio Astronomico di Collurania, 64100 Teramo, Italy
3Instituto
The French-Italian Concordia Station placed at Dome C, on the Antarctic Plateau at 3280 m above the sea level, will have the astronomical research as one of its main
activities. Preliminary studies have shown this site could be the best place known on Earth for astronomical observations at infrared and submillimeter wavelengths. The
IRAIT (International Robotic Antarctic Infrared Telescope) project, based on a 80 cm aperture telescope, will be the first European Infrared telescope at Dome C, and it is
planned to be in operation by the end of 2006. The University of Granada and the Institute for Space Studies of Catalonia (IEEC) contribute to the IRAIT project by developing
the moving optical system for the secondary and tertiary mirrors of the telescope, including the design and construction of both mirrors, the mechanical supports, the
electronics and the control software. Both institutions will also develop, in a second phase of the project and in collaboration with the University of Nice, a spectro-photometer
for near infrared observations.
Meteorological conditions
Mean air temperature
Minimum air temperature
Mean air temperature in summer
Mean air temperature in winter
Mean wind speed
Maximum wind speed
Mean air pressure
Yearly precipitation range (snow)
Lat: 75°06’25” S
Long: 123°23’44” E
Alt: 3280 m (osl)
The "noisy building" hosts the
workshop, the waste water
treatment plant, the
communication room, the
kitchen and the restaurant;
Eleven container size modules
houses the electric power plant,
the boiler room and a second
workshop
Dome C was originally selected for glaciological reasons. But Dome C has
many other valuable characteristics which make it a good site for:
• Studying the ozone hole.
• Solid Earth geophysics.
• Studying the Earth magnetic field.
• Evaluating techniques and procedures for future work on other planets.
• Studying the behavior of small groups of people in conditions close to those
encountered in space vehicles or orbital stations.
The best Astronomical site on the Earth?
• Low atmospheric temperature Æ low sky emissivity:
(Burton et al. 2001) mJy/(arcsec)2 ratio with standard
latitudes
K(2.2µm)
0.1
20 to 100
L(3.8µm)
100
20
20
N(10µm)
2·104
• Low water vapor content in the atm Æ high atmospheric transparency in the IR and submm/mm
• High Atmospheric Stability Æ low temporal and spatial sky noise
• Low turbulence at high altitudeÆ good seeing (fig.) and low scintillation
• More than 3 months of “night” Æ continuative monitoring of variable sources also in the
optical
• Presence of a permanent winter Station Æ Concordia Station
• Fast data transmission Æ placed In the line of sight of geostationary satellites (AUSAT)
The “quite building”
hosts the
bedrooms, the
laboratories and the
hospital.
The French-Italian Concordia
winter Station will be completed
by the year 2005.
The International Robotic Antarctic Infrared Telescope
(IRAIT) project goal is to install a 80-cm telescope equipped
with AMICA (Antarctic Mid-Infrared Camera) at Dome C.
Institutions involved in the project:
• University of Perugia - Italy
• INAF - Teramo Observatory - Italy
• University of Granada - Spain
• IEEC-CSIC-UPC of Barcelona - Spain
The project was funded by:
• 90% Italy Æ PNRA (Telescope), INAF (AMICA)
• 10% Spain
Total Project Cost ~1.3 MEur
Optical scheme
Classical Cassegrain +
2 Nasmyth station
• Primary Mirror
Diameter: 800 mm
• Focal Ratio of the
primary:
3
• Tolal Focal Ratio: 20
Nov. 2005
Enclosure
Container dimension: 3500 x
3500 x 6550 mm and standard
ISO 20 for transportation.
Opening system for the walls
and ceiling motorized and
remote controlled.
-50.8 °C
-84.6 °C
-30.0 °C
-60.0 °C
2.8 m/s
17 m/s
645 hPa
2-10 cm
Dec. 2005
Feb. 2006
Jan. 2006
(Aristidi et al. 2004)
Concordia is 1200 km from the coast. It can be reached: by tractor trains from Dumont D'Urville
(DDU) and by ski equipped planes from Baia Terra Nova and Dumont D'Urville.
The Telescope has a steel stiff Alt-Az
mount designed taking into account:
environmental condition (climatic data,
“diamond dust” problem, transportation);
maintenance & installation (handling
tools, modularity in all the parts); a
redundancy strategy for the critical parts
was also implemented.
Antarctic Mid-IR Camera (AMICA)
The array is a Si:As BIB 128x128 pixels
moderate-flux type, operating between
2-28 µm, manufactured by DRS
Technologies. Charge capacity of up to
107 e-; readout noise of 500 rms e-, at
the maximum frame rate of 500 s-1. The
QE @ 10-20 µm is about 60%. The
operating temperature (~5K) is obtained
by a closed-loop cryocooler. Scale of
1.94 arcsec/pixel and total FOV of 4×4
arcmin2.
Dome C
(designed by NTE S.A.)
Mechanical capabilities
The telescope disposes of:
• A nodding system implemented in M2.
• A chopping system implemented in M2 in order to
avoid excess thermal background.
• A rotation mechanism implemented in M3 to provide
observation in either of both Nasmyth focus.
Control Software
The Telescope/Camera control software follows a
client/server architecture and is distributed over: PCs
(high-level and co-ordination services); microprocessor
based systems (for real-time control purposes). The
object-oriented control software is designed to run
under Windows operating system an it is written in
C++. It is under test at the Coloti Astronomical Station.
Scientific Goals
• Mid-IR wavelengths: stars
• Red Galactic objects, interactions between stellar fluxes
and the ISM.
• Variability studied with repeated observations (long obs.
time).
• Very cool objects: brown dwarfs & giant planets.
• A sample of galaxies at low z (< 0.1) accessible to study
colours, SF bursts. IR bright galaxies etc.
• Moreover, ~30-40 known Blazars reachable.
• ToO:e.g Gamma Ray Bursts, Blazars in flare state.
• Follow-up : ALMA, VLT, AGILE, GLAST, SWIFT, etc.
Conclusions
• IRAIT will be the first European
Infrared telescope operating on the
Antarctica Plateau.
• It is planned to be in operations at
Dome C during Summer 2006-2007
and possibly for winterover operations
in 2007.
• It will offer a unique opportunity to
test the astronomical quality of the
Dome C site that has long believed
to be the best on Earth for
near and mid infrared
IRAIT
observations.