Feasibility of a Small, Rapid Optical/IR Response, Next Generation Gamma-Ray Burst Mission

Abstract

We present motivations for and study feasibility of a small, rapid-optical/IR response gamma-ray burst (GRB) space observatory. By analyzing existing GRB data, we give realistic detection rates for X-ray and optical/IR instruments of modest size under actual flight conditions. Given new capabilities of fast optical/IR response (~1 s to target) and simultaneous multi-band imaging, such an observatory can have a reasonable event rate, likely leading to new science. Requiring a Swift-like orbit, duty cycle, and observing constraints, a Swift-BAT scaled down to 190 cm2 of detector area would still detect and locate about 25 GRB yr-1 for a trigger threshold of 6.5σ. About 23% of X–ray located GRB would be detected optically for a 10 cm diameter instrument (~6 yr-1 for the 6.5σ X-ray trigger).