FASTTRAC II near-IR adaptive optics system for the Multiple Mirror Telescope: description and preliminary results

A new adaptive optics system has been constructed for moderately high resolution in the near infrared at the Multiple Mirror Telescope (MMT). The system, called FASTTRAC II, has been designed to combine the highest throughput with the lowest possible background emission by making the adaptive optical element be an existing and necessary part of the telescope, and by eliminating all warm surfaces between the telescope and the science camera's dewar. At present, only natural guide stars are supported, but by the end of 1995, we will add the capability to use a single sodium resonance beacon derived from a laser beam projected nearly coaxially with the telescope. In this paper, we present a description of FASTTRAC II, and show results from its first test run at the telescope in April 1995.