High-Resolution Fiber-Fed Spectrograph for the 6-m Telescope of the Special Astrophysical Observatory of the Russian Academy of Sciences: Assessment of Efficiency

摘要

We report the results of laboratory tests of the first version of the high-resolution fiber-fed spectrograph designed for the Special Astrophysical Observatory of the Russian Academy of Sciences (SAO RAS). During laboratory tests a spectral resolution of about 70 000 was achieved. The peak efficiency of the entire optical path of the spectrograph (without light losses at the CCD, primary mirror of the 6-m telescope, and in the atmosphere) at 620 nm and with the equivalent slit widths of the 1 ''.5 and 0 ''.75 are equal to 8% and 4%, respectively. The resolving powerR= 70 000 and 100 000 can be reached with the sky aperture 0 ''.75 and 0 ''.4 respectively. In the current version of the spectrograph these regimes of operation are implemented by mechanic aperturing of the slit. A dedicated projecting camera has been developed and is currently manufactured to operate with a collimated 200-mm diameter beam, which will make it possible to increase the spectral resolution up to 100 000. A two-beam image slicer will be used to maintain the luminous efficiency of the instrument at least at the 6% level.