The Goodman Spectrograph

The Goodman Spectrograph is an imaging, multi-object spectrograph for the SOuthern Astrophysical Research telescope (SOAR). It is one of the first designed to take advantage of Volume Phase Holographic (VPH) gratings by employing an articulated camera. This aspect of the mechanical design has had complicating effects on a number of usually simple systems, and has led to some unorthodox solutions. The spectrograph is also highly optimized for efficiency from 320 to 850 nm, and designed for rapid configuration changes, so that its throughput makes it competitive with instruments on larger telescopes. We present the high level requirements that have driven the mechanical and electronic systems, and show their implementation in the completed instrument. It is too early to assess the overall system performance, but tests of the modular subsystems show promising results. We discuss the expected overall performance and discuss mitigation strategies should that performance fall short of our goals.