PISCO: the Parallel Imager for Southern Cosmology Observations

We present the design and lab performance of the Parallel Imager for Southern Cosmology Observations (PISCO), a photometer for the 6.5 m diameter Magellan telescopes that produces g^l, r^l, i^l, and z^l band images simulta- neously within a 9 arcminute field of view. This design provides efficient follow-up observations of faint sources, particularly galaxy clusters and supernovae. Simultaneous imaging speeds the observing cadence by at a factor of ~ 3 (including optical losses) compared to other photometric imagers. Also, the determination of color (flux ratio between bands) is relatively immune to time variations in gray opacity due to clouds, so observations can proceed in less than optimal conditions. First light is expected in September 2014 2014.