Calibrating Broad Band X-ray Telescope

The on-axis effective area calibration for the central detector elements was performed using data from the Crab Nebula, while other carefully selected targets were used for calibration of the outer detector elements. The remaining systematic uncertainties in the effective area calibration for point sources observed both on and off axis are generally less than 5%-10%. The energy scale is known to better than 0.5% at 6.0 keV for both detectors.

The results presented here have an impact on the calibration of other medium resolution X-ray experiments such as the CCDs on board ASCA (Astro-D) as well as the Advanced X-Ray Astrophysics Facility detectors.