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NICMASS at the Feed--Update (1Dec95) (from KPNO, NOAO Newsletter No. 44, December 1995) As reported in the September 1995 NOAO Newsletter No. 43, the University of Massachusetts NICMASS HgCdTe camera has been utilized successfully for high-resolution spectroscopy at the Coude Feed Spectrograph. A well-blocked narrowband filter at 1.624u used with either grating B (R = 7000) or grating E (R = 43000) restricts the thermal background to that within the filter bandpass, and integration times up to 6000 s are possible. Although the quantum efficiency of HgCdTe falls significantly with decreasing wavelength, it is still in the range 0.15-0.2 at 1.083u, more than an order of magnitude greater than that of a Si CCD. Until the commissioning of the high-resolution InSb spectrograph PHOENIX (see accompanying article), NICMASS on the Coude Feed will provide R = 43000 capability at this wavelength. Because one operates in 52nd order with grating E at 1.083u, a narrow order separation filter is required to isolate the order and block thermal radiation from the spectrograph. The filter presently in NICMASS suffers from significant extraband leakage; the leakage problem has been solved by use of a series blocking filter, but at a cost of a full magnitude in transmission. A custom well-blocked filter is on order. Notwithstanding the modest detector quantum efficiency and present filter transmission, small telescope aperture, and high spectral resolution, our limited experience at 1.083u suggests that this instrument can be a powerful scientific tool for relatively bright objects in this wavelength regime. We will continue to offer this system for shared-risk observing at the Coude Feed Spectrograph. Prospective observers should familiarize themselves with the system and its operation by reference to the description on the World Wide Web at http://scruffy.phast.umass.edu/Irlab/NICMASS/nicuser.html or by contacting the undersigned, rjoyce@noao.edu or khinkle@noao.edu, for information regarding a specific application. [Figures not included] Spectrum of the late-type giant HD 6833 (V = 6.75; J = 4.64) using the echelle grating at a resolving power of 43,000 (Sneden et al., in preparation). This is the average of four 1-hr integrations. Spectrum of HR 1105, a bright S-type emission line star, showing the P-Cygni profile of the He I line at a resolving power of 43,000. Dick Joyce, Ken Hinkle
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