WST, the wide-field spectroscopic telescope: progress on the design of the instruments

WST – the Wide-field Spectroscopic Telescope is a proposed new facility that will provide a transformational gain in spectroscopic survey capability over existing facilities. The WST is a 12 metre class telescope equipped with instrumentation to provide simultaneous observations in both multiple-object spectroscopy and integral field spectroscopy modes. This paper will describe the status of the instruments being designed for the WST. The wide-field of view of the telescope, 2 degrees in diameter, will illuminate a fiber-fed multiple-object spectrograph capable of observing 30,000 objects at low spectral resolving power, and 2,000 objects at spectral resolving power of R = 40,000. An overview of the fiber positioner technology, and fiber relay system, will be provided. At the centre of the telescope’s field of view an optical relay system will direct light to a large integral field spectrograph with a 3 arc-minute by 3 arc-minute field of view. An overview of the designs of the low-resolution, of the high-resolution, and of the integral field spectrographs will be presented. Technology advancements are being investigated to make the spectrographs more optically efficient and sustainable, such as CMOS detectors with low power cooling systems. The WST facility will include an advanced calibration system capable of illuminating the spectrographs with a variety of light sources and providing metrology function for the fiber positioners. Finally, an overview of the overall layout of the instruments within the WST facility will be provided.