Design of a CZT Gamma-Camera for GRB and Fast Transient Follow-up: a Wide-Field-Monitor for the EDGE Mission

TL;DR

This paper presents a wide-field CZT gamma-ray camera design for the EDGE mission, enabling real-time detection and localization of transient gamma-ray events with high sensitivity and arcminute accuracy.

Contribution

It introduces a novel CZT-based gamma-camera concept with large-area, high-resolution detectors for fast transient follow-up in space missions.

Findings

Achieves 0.4 ph cm-2 s-1 sensitivity in 1s

Provides arcminute localization over 3 sr sky region

Enables autonomous, real-time source positioning

Abstract

The success of the SWIFT/BAT and INTEGRAL missions has definitely opened a new window for follow-up and deep study of the transient gamma-ray sky. This now appears as the access key to important progresses in the area of cosmological research and deep understanding of the physics of compact objects. To detect in near real-time explosive events like Gamma-Ray bursts, thermonuclear flashes from Neutron Stars and other types of X-ray outbursts we have developed a concept for a wide-field gamma-ray coded mask instrument working in the range 8-200 keV, having a sensitivity of 0.4 ph cm-2 s-1 in 1s (15-150 keV) and arcmin location accuracy over a sky region as wide as 3sr. This scientific requirement can be achieved by means of two large area, high spatial resolution CZT detection planes made of arrays of relatively large (~1cm2) crystals, which are in turn read out as matrices of smaller pixels. To achieve such a wide Field-Of-View the two units can be placed at the sides of a S/C platform serving a payload with a complex of powerful X-ray instruments, as designed for the EDGE mission. The two units will be equipped with powerful signal read out system and data handling electronics, providing accurate on-board reconstruction of the source positions for fast, autonomous target acquisition by the X-ray telescopes.