Speaker
Description
Atmospheric Cherenkov telescopes observe cosmic gamma rays with energies
upwards of twenty giga electronvolt in collecting areas which exceed the
collecting areas of satellites by orders of magnitude. However, as we further
push the concept of the Cherenkov telescope array, the intrinsic limitations of
imaging itself become more evident. Aberrations limit our field of view and the
angular resolution in the gamma ray sky. Further, the narrowing depth of field
in larger telescopes prevents us from lowering the energy threshold for
cosmic gamma rays. While aberrations can to some extent be mitigated by more
complex optical surfaces, the narrowing depth of field is a physical limitation
which can not be overcome by spending more resources. We investigate a novel
class of instrument for the atmospheric Cherenkov method which is practically
free of aberrations and which turns the narrowing depth of field into the
perception of the airshower's depth. We call it the Cherenkov plenoscope.
Beside widening the field of view and sharpening our view into the gamma ray
sky, the Cherenkov plenoscope might further enable the next generation to build
a timing explorer which can collect cosmic gamma rays with energies down to one
giga electronvolt in effective areas several orders of magnitude larger than
the collecting areas of satellites. We will introduce the concept behind the
Cherenkov plenoscope and give an outlook on a specific design for a one giga
electronvolt timing explorer.
