HRS

The SALT HRS is a dual-beam (370-550 nm & 550-890 nm) fibre-fed, white-pupil, échelle spectrograph, employing VPH gratings as cross dispersers.  The cameras are all-refractive.  SALT HRS is an efficient single-object spectrograph using pairs of large (350 μm and 500 μm; 1.6 and 2.2 arcsec) diameter optical fibers, one for source (star) and one for background (sky).  Three of the pairs feed image slicers before injection into the spectrograph, which delivers resolving powers of R ~14,000 (unsliced 500 μm fibres), ~40,000 (sliced 500 μm fibres), and ~65,000 (sliced 350 μm fibres).  A single 2k x 4k CCD captures all of the blue orders, while a 4k x 4k detector, using a fringe-suppressing deep-depletion CCD, is used for the red camera.  Complete free spectral ranges are covered by both the blue and red arms. More technical details of HRS can be obtained at the Durham University Centre for Advanced Instrumentation (who built HRS) website.

More information is available from the following documents.

• Call for science verification observations
• Call for expressions of interest
• HRS instrument description
• HRS functional performance requirements
• HRS operational concept definition
• HRS optical design
• HRS commissioning plan
• Performance of the SALT High Resolution Spectrograph
• SPIE 2008 paper
• SPIE 2010 paper
• SPIE 2012 paper
• SPIE 2014 paper