The ABRIXAS X-Ray All Sky Survey
on behalf of the MPE-ABRIXAS-Team
ABRIXAS is a small X-ray satellite mission to be launched in 1999. During the nominal mission duration of three years it will scan the sky six times in the energy band 0.5 - 10 keV, with an angular resolution of better than < 1 arcmin and a limiting sensitivity similar to that of ROSAT at 1 keV.The spectral resolution will be comparable to that of the XMM-EPIC detector ( ~ 150 eV at 6.7 keV).
The general scientific objective will be to extend the ROSAT all sky survey information (0.1-2.4 keV) out to 10 keV and to act as a pathfinder for XMM, AXAF and ASTRO-E. The total number of detected source will be ~ 60.000. Specific objectives are to detect sources obscured by photoelectric absorption in the galactic plane and center directions to map the diffuse hard X-ray diffusion emission of the galactic ridge and to detect Seyfert-2 galaxies and Quasars-2 , to map clusters of galaxies with an unlimited field of view and to measure the time variability on scales from seconds to years.
ABRIXAS carries seven Wolter-I telescopes with 27 nested mirrors each, having focal lengths of 1.6 m. They look simultaneously at seven different fields in the sky, each about 40' in diameter and separated from each other by 7.25°. The seven foci share one 6cm x 6cm pn-CCD array which is identical to that developed by MPE for XMM-EPIC. The X-ray mirrors are scaled down versions of the XMM mirrors with largely identical grazing angles.
The project is a scientific collaboration between MPE, AIP Potsdam and IAAT T=FCbingen. It is managed by DARA/DLR. The satellite contractor is OHB Bremen and the mirrors are produced by Carl Zeiss using replication techniques. The launch in spring 1999 on a Russian Kosmos rocket will put ABRIXAS into a ROSAT-like orbit (51°, 580 km) enabling the use of the Weilheim groundstation of GSOC/DLR.