Tom Barnes, University of Texas and McDonald Observatory
The instrumentation suite of the HET will ultimately include a prime focus Low Resolution Spectrometer (LRS PI Gary Hill, CCD PI Phillip MacQueen, McDonald Observatory), a fiber-fed High Resolution Spectrometer (HRS PI Robert Tull, CCD PI Phillip MacQueen, McDonald Observatory), and a fiber-fed Medium Resolution Spectrometer (MRS PI Larry Ramsey, Pennsylvania State; CCD PI to be determined). During this first Public Access period, the LRS and HRS will be available. The MRS is expected to be commissioned after this initial Public Access period and will then be available under this program.
The LRS is described by Hill et al. (SPIE, 3355-20, 1998), Cobos D. et al. (SPIE, 3355-71, 1998) and Hill et al. (SPIE, 3355-74, 1998). It is a grism spectrometer with imaging, long-slit, and multi-object capability. (Multi-object capability will not be available in this first Public Access period.) The field of view is 4' in diameter. Two grisms are currently available—grism 1 covers 410 to 1000 nm at R~600 and grism 2 covers 430 to 740 nm at R~1300. Resolutions are quoted for a 1.0" wide slit. Slit widths of 1.0", 1.5", 2.0", 3.0", and 10.0" by 4' long are available. The CCD is a Ford Aerospace 3072×1024 device with 15 µm pixels, and the image scale is ~0.25" per pixel. The LRS entered instrument commissioning in April 1999; it is now in research operation. Initial performance characteristics of the LRS are available at http://www.noao.edu/gateway/het. These will be updated as they are refined.
The HRS is a single channel adaptation of the ESO UVES spectrometer as described by Tull (SPIE, 3355-21, 1998). It uses an R-4 echelle mosaic with cross-dispersing gratings to separate spectral orders. An all-refracting camera images onto a mosaic of two thinned and anti-reflection coated 2K×4K CCDs with 15 µm pixels. The CCDs are abutted along their 4K side with an ~69 pixel dead space between them. This dead space is approximately parallel to the spectral orders. Resolving powers of R ~ 30,000, 60,000, and 120,000 will be available by means of three effective slit widths. Spectral coverage is 420-1100 nm. The HRS is expected to enter instrument commissioning in March 2000. Potential researchers should take note that instruments occasionally slip schedule and that there is some risk of this for HRS in the summer of 2000. Projected performance characteristics of the HRS are available at http://www.noao.edu/gateway/het. These will be updated as instrument commissioning proceeds.