This document provides information useful to Night Attendants
and Observing Assistants for performing nighttime
troubleshooting of DEIMOS.
DEIMOS Quick Facts
- DEIMOS is a low-to-moderate resolution optical
spectrograph and imager capable of working through most of the
- It is a mounted at the Nasmyth focus of Keck II. The
whole instrument rotates to keep a fixed orientation (PA mode)
- DEIMOS is mainly used with large slitmasks for
multi-object spectroscopy but it can also perform single
object long-slit spectroscopy and be used as an imager.
- DEIMOS is most notable for the very large field of view
it offers which means a very large number of objects can be
Common Nighttime Problems