Development of multi-object spectroscopy unit for simultaneous-color wide-field infrared multi-object spectrograph

Abstract

SWIMS (Simultaneous-color Wide-field Infrared Multi-object Spectrograph) has a multi-object spectroscopic function including IFU in addition to the imaging capability. The mechanism in order to achieve this function is Multi-Object Spectroscopy Unit. This is the function that can derive spectra of simultaneous 20–30 objects over range from 0.9 to 2.5μmm. To set or exchange a slit mask on telescope focal plane, MOSU consists of the slit-mask dewar (carrousel), focal plane dewar, and robotic arm called mask catcher. There are many structural and mechanical features in MOSU to achieve its performance in cooling system, positional repeatability of slit mask and so on. We present here its unique components and its specifications and performance.