Science drivers and first generation instrumentation for the Southern African Large Telescope

摘要

This paper describes the science drivers and first generation instrumentation capabilities of the Southern African Large Telescope (SALT), due to begin science operations in late 2004/early 2005. First generation instruments are confined to the visible spectrum, but optimized for UV performance, with capability to ～320 nm. Instrumentation will have access to a circular 8 arcmin diameter science field, with guidance objects outside of this region (< 5 arcmin off-axis). Although SALT will have active mirror control to optimize image quality, the mirror array will not be phased (in it's first light configuration), so adaptive optics are not planned initially and instruments will be optimized to the median seeing conditions (0.9 arcsec FWHM). The telescope design, based on the Hobby-Eberly Telescope (HET), also necessitates a queue-scheduled observing approach, which is ideal for time resolved studies of astrophysical phenomena on timescales of >days. Time resolved studies are an important aspect of the overall SALT science drivers. Special efforts are being made to ensure high time resolution capability by employing frame transfer CCDs on two of the first-light instruments, the imaging spectrograph (PFIS/MPALAS) and imaging camera (SALTICAM). Time resolutions of ～50 ms for spectroscopy, with zero dead-time, are planned. Instrument capabilities, which include polarimetry, Fabry-Perot imaging spectroscopy and high resolution fibre-fed spectroscopy (HRS/CELESTTA), will ensure that the major science goals of SALT s partners are realized.