Coded-aperture x- or γ-ray telescope with least-squares image reconstruction. III. Data acquisition and analysis enhancements

Abstract

The previously described design of a cosmic x- or γ-ray telescope with least-squares image reconstruction has been enhanced to provide for mask-antimask operation. This cancels and eliminates uncertainties in the detector background. The simulations of its operation have been made more realistic by incorporating instrumental blurring of sources. A second-stage least-squares procedure determines the precise positions and total fluxes of point sources responsible for clusters of above-background pixels in the field resulting from the first-stage reconstruction. Another program converts source positions in the image plane to celestial coordinates and vice versa, the image being a gnomic projection of a region of the sky. A complete sky-to-sky simulation of the imaging of a source field is presented. It is demonstrated that the point-spread function of the overall imaging process is essentially perfect.