Extending the Echidna concept: A proposal for a 2000+ multi-fiber positioner

Abstract

The Echidna concept is an attractive solution to performing wide-field spectroscopy in fast beam systems (around F/2.5 or faster) where traditional pick and place multi-fiber positioners are not viable. We introduce a concept design for a 2000+ fiber Echidna-style positioner for the prime focus of a telescope optimized for wide field spectroscopy. A summary of the original 400-fiber Echidna positioner for the Subaru prime focus is presented. The natural extension of this design to a 2000+ fiber system is discussed. Two proposals currently under development incorporating such a positioner are introduced. The 2250 fiber Ukidna spectrograph is a stellar radial velocity engine for the UK Schmidt telescope at Siding Spring Observatory. More ambitious is the 4000 fiber Kilo-Aperture Optical Spectrograph (KAOS) enabling the 8-m Gemini telescopes with a 1.5° field of view for multi-object spectroscopy. Both instruments offer an order of magnitude increase in spectroscopic survey power compared with current day facilities.