|: Dark matter from Ellipticity Sources CARTography|
Gravitational distortion maps over very large fields permit to explore
the large-scale distribution of the (dark) matter in the universe without
regard on the light (galaxy and gas) distribution. By using this technique,
it is possible to study the cosmic mass fluctuations.
The gravitational shear produced by the cumulative effect of the matter along the line of sights can be recovered from the gravitational distortion which increases the ellipticity of the galaxies. From these distortion patterns we can in principle
A set of slides (general and talks) is available on our new DESCART web site in construction.
The project is aiming at mapping gravitational distortions in a field of about 100 deg^2. This is one of the main scientific goals of the MegaPrime project, that includes a refurbishing of the prime-focus of CFHT and the building of a wide field CCD camera MEGACAM under the responsablity of DAPNIA/SAp (CEA Saclay). The image processing will be done at the TERAPIX center, located at IAP.
Beyond the intrinsic scientific interest of projected mass mappings (which is discussed here) this project is part of a global search, with all possible observational means, of the large-scale structures of the Universe. Particularly interesting complementary tools will be available in the coming years, namely the VIRMOS instrument on the VLT and the XMM satellite for X-ray mapping of the deepest potential wells.
The project develops tools in order to produce robust results:
The new DESCART web site in construction. describes these tools and provides continuous progress reports on the project.
Last changes, 2003, December 20