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Proceedings Paper

ESI: a new spectrograph for the Keck II telescope
Author(s): Brian M. Sutin
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Paper Abstract

The ESI (echellette spectrograph and imager) is a multi-mode Cassegrain spectrograph currently funded and under construction at UCO/Lick Observatory for the Keck II telescope. The ESI instrument has three modes. The 170.0-mm collimated beam can be sent directly into the camera for imaging, through a prism disperser, or to an echellette grating with prism cross-dispersion. An all-refracting Epps camera and a single 2 K by 4 K detector are used for all three modes. The direct-imaging mode has a 2.0 multiplied by 8.0- arcmin field of view with 0.15-arcsec pixels. Filters may be placed either near the focal surface of the telescope or in the parallel beam, and the option of a future upgrade including a Fabry-Perot at the pupil image is available. The low-dispersion prism-only mode has a dispersion of 50 to 300 km/sec/pix, depending on wavelength, and this mode can be used with a 8.0-arcmin long slit or in a multi-slit mode with user- made slit-masks. The high-dispersion echellette mode gives the entire spectrum from 0.39 to 1.09 microns with a 20.0-arcsec slit length in a single exposure, with a dispersion of 9.6 to 12.8 km/sec/pix.

Paper Details

Date Published: 21 March 1997
PDF: 10 pages
Proc. SPIE 2871, Optical Telescopes of Today and Tomorrow, (21 March 1997); doi: 10.1117/12.268998
Show Author Affiliations
Brian M. Sutin, Univ. of California/Santa Cruz (United States)

Published in SPIE Proceedings Vol. 2871:
Optical Telescopes of Today and Tomorrow
Arne L. Ardeberg, Editor(s)

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