Medium-Resolution Spectrograph

Recent Changes/UpdatesLinks
09 Feb 2004 Memo from Gary Hill about New guide stars limits
Aug 2002 Here is the SPIE MRS paper which describes the instrument
07 Aug 2002 First light

MRS availability for HET community in 2003-2

The medium resolution spectrograph (MRS) is currently in commissioning and the basic single object "Direct Feed" mode in the visible beam has been tested. This mode will be available for queue-scheduled observations starting in April 2003. The direct feed mode, which utilizes what the MOS 0 probe, has a object/sky pair of blue optimized (Polymicro Technologies (PT) FVP300330370500) and red optimized (PT FIP 300330370500) fibers that project to 1.5 arc-seconds on the sky and yield a fixed resolution of about 7000. The object and sky fibers are separated by about 10 arc-seconds. There are also single 2 arc-sec red or blue optimized fiber options that yield a resolution of about 5000. These modes have all been tested with cross-disperser #1 with peak efficiency at 600 nm and efficiency above 2/3 peak over the 450 to 900 nm range available. Quantitative data taken during the Dec run with poor image quality, EE50 from 2 to 3 arc sec, was used to estimate performance. For a S/N=100 per pixel in 1800 sec we obtain a limiting magnitude of R~ 13.8 at a resolution of 7000; i.e. the 1.5 arc sec fiber, and R~ 14.2 for a resolution of 5000, i.e. a 2 arc sec fiber. At the 2x2 binning used a pixel is about 0.02 nm.

Phase II details