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GRI: focusing on the evolving violent universe

Knödlseder, Jürgen; Christensen, Finn; Bazzano, Angela +4 more

The gamma-ray imager (GRI) is a novel mission concept that will provide an unprecedented sensitivity leap in the soft gamma-ray domain by using for the first time a focusing lens built of Laue diffracting crystals. The lens will cover an energy band from 200-1,300 keV with an effective area reaching 600 cm². It will be complemented by a…

History of gamma-ray telescopes and astronomy

Pinkau, Klaus

Gamma-ray astronomy is devoted to study nuclear and elementary particle astrophysics and astronomical objects under extreme conditions of gravitational and electromagnetic forces, and temperature. Because signals from gamma rays below 1 TeV cannot be recorded on ground, observations from space are required. The photoelectric effect is dominant <…

Gamma-ray telescopes. 400 Years of astronomical telescopes

Gehrels, Neil; Cannizzo, John K.

The last half-century has seen dramatic developments in γ-ray telescopes, from their initial conception and development through to their blossoming into full maturity as a potent research tool in astronomy. Gamma-ray telescopes are leading research in diverse areas such as γ-ray bursts, blazars, Galactic transients, and the Galactic distribution o…

Fresnel zone plate telescopes for X-ray imaging II: numerical simulations with parallel and diverging beams

Rao, A. R.; Girish, V.; Nandi, Anuj +4 more

We present the results of simulations of shadows cast by a zone plate telescope which may have one to four pairs of zone plates. From the shadows we reconstruct the images under various circumstances. We discuss physical basis of the resolution of the telescope and demonstrate this by our simulations. We allow the source to be at a finite distance…