This webpage is being kept for archival purposes only.
It may be updated in the future, but it is not currently being maintained.
It may be updated in the future, but it is not currently being maintained.
Context for development of EXIST
Need for Deep Hard X-ray Survey:
- HX band (~10-600 keV) is last band without imaging all sky survey
- Only HX survey from HEAO-A4 (1979) with sensitivity ~1/20 flux of brightest source (Crab)
- Soft X-ray (0.2-2keV) ROSAT survey (1990) with sensitivity ~0.0005 Crab flux
- Medium X-ray (2-10keV) ABRIXAS2 survey likely (German mission; c. 2002) to match ROSAT sensitivity
- Pointed HX missions (SIGMA/GRANAT; OSSE/CGRO; HEXTE/RXTE; PDS/BeppoSAX) reveal bright sources: AGN, galactic black holes and transients
- All sky HX monitor and crude imaging (BATSE/CGRO) show variable HX sky
- ASCA and BeppoSAX (1999) reveal large obscured AGN population
- BeppoSAX enables discovery that GRBs are at significant redshift
