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CEA/CFH/CNRS Joint Press Release
The MegaPrime structure installed on top of the Canada-France-Hawaii telescope
(CFHT)1 , is now available to scientists. At the heart of MegaPrime
is MegaCam, the biggest digital camera in the world. This camera is installed
at the newly built upper end of the CFHT at the optical center.. Images
will be processed at the TERAPIX data processing center located at the
Paris Astrophysics Institute. Scientists will thus be able to analyze
faint objects in a wide field and with a great degree of detail. MegaPrime
is the fruit of a joint project between the CFHT, the CNRS, the CEA (French
Atomic Energy Commission) and the National Research Council of Canada
(CNRC).
MegaPrime is a project developed by the Canada-France-Hawaii
telescope company. It was carried out in partnership with:
- DAPNIA (Department of Astrophysics, Particle Physics,
Nuclear Physics and Related Instrumentation) of the CEA (French Atomic
Energy Commission),
- the Laboratoire d’Etudes Spatiales et d’Instrumentation
en Astronomie (LESIA)2 of the Observatoire de Paris,
- the Herzberg Institute of Astrophysics of the National
Research Council of Canada,
- the Technical Division of the Institut National
des Sciences de l’Univers (INSU) of the CNRS,
- Paris Astrophysics Institute (IAP)3 .
The MegaCam camera was developed by DAPNIA of the CEA. This camera will
cover a surface of one square degree, the equivalent of four Full Moons.
It uses 40 high quality CCD4 detectors (including 10 million pixels each)
mounted in a mosaic of four rows of nine CCDs. These CCDs were developed
by a British company, e2v technologies (formerly Marconi Applied Technologies).
To increase the sensitivity of the detectors, their temperature is maintained
at less than 120° C: we thus obtain detectors that are several hundreds
of thousands times more sensitive than those used in digital cameras.
30-cm filters are used in front of the focal plane to choose wavelengths
of light in which the objects will be observed. Just like a traditional
camera, it is necessary to have a shutter that opens and closes at the
beginning and end of each exposure. The size of the camera is such that
it was necessary to develop a giant shutter measuring 1 m in diameter.
Since this camera is designed to be used at the optical center of the
CFHT, it was necessary to build a new front end, located 13 meters above
the main mirror of the telescope. It was designed by the CFHT, in conjunction
with the Technical Division of the INSU and built by a California company,
Erie Press Systems. An optical device, built by the Herzberg Institute
of Astrophysics and the French company, Sagem-Reosc, to which an image-stabilizing
unit developed by LESIA of the Paris Astrophysics Observatory is added,
completes the front end equipment.
Data thus transmitted by the MegaCam camera will be processed at the TERAPIX
data processing center (Traitement Elémentaire, Réduction
et Analyse des PIXels), located at the Paris Astrophysics Institute. TERAPIX
was installed in order to develop software, an automatic processing line
and analysis tools for images obtained with MegaCam. It will also produce
the images and documented catalogues of the major survey of the sky, the
CFHT Legacy Survey, that will be made with MegaCam, and will help astronomers
to more effectively process data from MegaCam. During the course of the
next five years, the TERAPIX center will process more that 50 Teroctets
of data and produce approximately 30,000 images that will be archived
at the Canadian Astronomical Data Center of the CNRC and made available
to French, Canadian and Hawaiian astrophysicists. TERAPIX is supported
by the INSU, the National Cosmology Program, DAPNIA of the CEA and the
IAP.
The CFHT Legacy Survey consists of three major surveys that will require
the use of the telescope for 100 nights per year over five years. These
observations will focus on the study of distant super novae, the distribution
and the evolution of galaxies, the study of stellar populations in our
galaxy and the analysis of objects in our solar system. These data will
provide information on the distribution of matter in the universe and
on its evolution.
When the overall quality of the instrument was initially assessed, test
observations made it possible to obtain very high quality results: the
discovery of new satellites around Jupiter, the observation of asteroids
passing through the Earth's orbit and an inventory of wide areas of the
sky to be observed within the framework of the CFHT Legacy Survey, leading
us to predict a productive future for this instrument.
1 - The Canada-France-Hawaii Telescope
Company (CFHT) works in partnership with the CNRS in France, the National
Research Center of Canada and the University of Hawaii. The telescope,
with a 3.6-meter mirror, is installed on top of Mauna Kea at 4,200 meters
in altitude on the island of Hawaii.
2 - CNRS, Universités Paris VI and Paris VII
3 - CNRS, Université Paris VI
4 - Charge Coupled Device
For more information:
MegaPrime site of the CFHT: http://www.cfht.hawaii.edu/News/MegaPrime/
MegaPrime site of the Technical Division of the INSU: http://www.dt.insu.cnrs.fr/megaprime/megaprime.html
MegaCam site of the Astrophysical Department of the CEA:
http://www-dapnia.cea.fr/Phys/Sap/Actualites/MEGACAM/indexmegacam0303_fr.shtml
TERAPIX site of the IAP: http://terapix.iap.fr/
Press contact:
CNRS: Martine HASLER
Tel: +33 1 44 96 46 35.
E-mail: martine.hasler@cnrs-dir.fr
CEA:
Pascal Newton
Tel: +33 1 40 56 20 97
E-mail: pascal.newton@cea.fr
TCFH researcher contact:
Christian VEILLET
Tel: +1808 885 3161
E-mail: veillet@cfht.hawaii.edu
CNRS-INSU contact:
Philippe CHAUVIN
Tel: +33 1 44 96 43 36
E-mail: Philippe.Chauvin@cnrs-dir.fr
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