Spectroscopic equipment for the Space Telescope

Abstract

The Space Telescope will provide views of the Universe of remarkable clarity. Central to its capabilities is an f/24 Ritchey-Chretien telescope with a 40000 cm 2 unobscured collecting area, which will provide point-source images less than 0.1" in radius at wavelengths below 633 nm. It will operate over the range 110 nm to 1 mm. The initial flight instrumentation includes two spectrographs, the Faint Object Spectrograph (F.O.S.) and the High-Resolution Spectrograph (H.R.S.). The F.O.S. is sensitive from 115 to 800 nm. It will provide data at resolving powers 10 3 -10 2 on extremely faint sources. The H.R.S. operates at the wavelengths 107-320 nm. It will achieve high photometric accuracy at resolving powers 10 5 , in the echelle mode, or 10 4 -10 3 in first order, on brighter targets. The two cameras on board the S.T. will provide ancillary spectroscopic capabilities.