EXIST

Energetic X-ray Imaging Survey Telescope

Science Objectives

This webpage is being kept for archival purposes only.
It may be updated in the future, but it is not currently being maintained.

EXIST Mission Design Drivers

Parameter Science Issues Design Impact
Maximum energy AGN and BH physics; polarization
Blazar spectral breaks
GRB redshifts (lumnosity-lag)
600 keV for Emax requires thick masks and depth-sensing detectors. Lower Emax (100-300 keV) could reduce mission mass by factor of ~2 and simplify detectors
Minimum energy Absorption signature
QPO BH signature
To go below 10 keV, ASIC readout noise must be reduced, along with the thickness (i.e., absorption) of the thermal shield/optical blocking layer
Angular Resolution* AGN counterpart IDs
GRB counterpart IDs
≤10' required, ≤2%#39; desirable (at <20 keV) and required small (0.5 mm) CZT pixels possible, but total channel count scales as square of angular resolution, and small pixels increase mask auto-collimation
FoV* Systematic limits on sensitivity
GRB low-E sensitivity
Large total FoV required to catch rare events and to monitor BH transients on orbital time-scale, but the FoV for individual imaging elements must be <30 degrees or background emission will ruin S/N. Smaller FoV also increases low-E sensitivity.
Number of telescopes Instantaneous vs. full-sky survey coverage Mass change

* Possibly different in different telescopes.

More will be added to this, with text descriptions.