A photon-counting imaging Fabry-Perot spectrometer for kinematic studies of extended astronomical objects

Velocity field mapping in extended astronomical sources like gaseous nebulae and galaxies as well as nebulosities surrounding certain stars is important to understand the relevant physical phenomena occurring in such objects. A seeing-limited imaging Fabry-Perot Spectrometer has been constructed for such an endeavour which uses an imaging photon-counting detector. Details of the optics, the detector and the performance of the instrument are described here.