Instrument Information
IDENTIFIER urn:nasa:pds:context:instrument:irtf-maunakea.3m2.spex::1.2
NAME SPEX
TYPE
DESCRIPTION Up-to-date as of October 12, 2023 from the IRTF/SpeX websiteIntroductionSpeX is a medium-resolution 0.7-5.3 micron spectrograph built at the Institute forAstronomy (IfA), for the NASA Infrared Telescope Facility (IRTF) on Mauna Kea. Theinstrument saw first light in May 2000 and was upgraded in 2014. The primary reasonfor the upgrade was to replace obsolete array control and instrument controlelectronics although the opportunity was taken to upgrade the arrays as well. TheRaytheon Aladdin 3 1024x1024 InSb array in the spectrograph was replaced by aTeledyne 2048x2048 Hawaii-2RG array and the engineering grade Aladdin 2 512x512 InSbarray in the IR slit viewer was replaced by the science grade Aladdin 3 array fromthe spectrograph (only a 512x512 quadrant is used). Astronomical Research Cameras,Inc. controllers run both arrays. Most of the warm electronic hardware was alsoreplaced: motors, motor controllers, Hall effect sensor control, power supplies,computers and GUIs.For most observing programs guiding is done with the IR slit viewer on spillover fluxfrom the object in the slit. However, for optically visible objects selectable IRtransmitting and visible reflecting dichroics in SpeX feed the MORIS CCD cameraattached to the side of SpeX to enable guiding in the visible. MORIS is also used asa scientific CCD imager and for simultaneous optical and IR observations inconjunction with SpeX.The upgrade has resulted in increased simultaneous (one shot) wavelength coverage inall spectral modes and improved spectral sensitivity (0.25-0.5 mags). Due to thefaster computers instrument control is more robust and there are fewer softwareproblems.SpeX was originally funded by the National Science Foundation (NSF) in 1996 withadditional funding from NASA for the detector arrays in 1998. The SpeX Upgrade wasfunded by NSF in 2008 but delays in procurement of a science grade H2RG array delayedcompletion until 2014.New Spex (Aug 2014-)--------------------? Spectrograph pixel size 0.10" (18 microns)? Slit widths: 0.3", 0.5", 0.8", 1.6" and 3.0"? PRISM 0.7-2.52 micron, R~200 matched to 0.3x15" slit or 0.3x60" slit? SXD 0.7-2.55 micron, R~2000 matched to 0.3x15" slit? LXD_short 1.67-4.2 micron, R~2500 matched to 0.3x15" slit? LXD_long 1.98-5.3 micron, R~2500 matched to 0.3x15" slit? Single order short 0.9-2.4 micron, R~2000 matched to a 0.3x60" slit? Single order long 3.1-5.3 micron, R~2500 matched to a 0.3x60" slit? Slit viewer: 60x60" FOV at 0.12" per pixel, selection of filters available (no change)Old SpeX (2000-Jan 2014)------------------------? Spectrograph pixel size 0.15" (27 microns)? Slit widths: 0.3", 0.5", 0.8", 1.6" and 3.0"? PRISM 0.8-2.5 micron, R~200 matched to 0.3x15" slit or 0.3x60" slit? SXD 0.8-2.4 micron, R~2000 matched to 0.3x15" slit? LXD1.9 1.95-4.2 micron, R~2500 matched to 0.3x15" slit? LXD2.1 2.15-5.0 micron, R~2500 matched to 0.3x15" slit? LXD2.3 2.25-5.5 micron, R~2500 matched to 0.3x15" slit? Single order short 0.9-2.4 micron, R~2000 matched to a 0.3x60" slit? Single order long 3.1-5.4 micron, R~2500 matched to a 0.3x60" slit? Slit viewer: 60x60" FOV at 0.12" per pixel, selection of filters available
MODEL IDENTIFIER
NAIF INSTRUMENT IDENTIFIER
SERIAL NUMBER
REFERENCES Rayner, J.T., P. M. Onaka, M. C. Cushing and W. D. Vacca, Four Years of Good SpeX, inGround-based Instrumentation for Astronomy, A. F. M. Moorwood and M. Iye, Eds.,Proceedings of the SPIE, vol. 5492, pp. 1498-1509, 2004, doi:10.1117/12.551107.

Rayner, J. T., D. W. Toomey, P. M. Onaka, A. J. Denault, W. E. Stahlberger, and 3others, SpeX: A Medium-Resolution 0.8 - 5.5 micron Spectrograph and Imager for theNASA Infrared Telescope Facility, PASP 115, 362, 2003, doi:10.1086/367745.