The Lightspeed project: high-speed, ultra-low read noise imaging and polarimetry for the Magellan telescopes

Abstract

Lightspeed will be an ultra-fast (> kHz), ultra-low read noise, multicolor (ugriz + IR) imager for the 6.5 meter Magellan Clay telescope. In a single-channel configuration, Lightspeed will also enable single-shot linear polarimetry, narrowband imaging, or white-light imaging. Lightspeed is designed around groundbreaking single-photon-resolving detector technologies: deep sub-electron read noise CMOS image sensors from Fairchild Imaging and a HgCdTe avalanche photodiode array from Leonardo. Here we present Lightspeed's basic optical design concept, predict its on-sky performance, and highlight science cases that Lightspeed has the potential to revolutionize. Lightspeed builds upon the success of proto-Lightspeed, a single-channel prototype employing commercial-off-the-shelf re-imaging optics. proto-Lightspeed is now available as a PI instrument on the Clay telescope. We also discuss the current status of proto-Lightspeed and lessons learned from its commissioning, applicable to the development of Lightspeed and any other instrument seeking to integrate scientific CMOS image sensors.