The Apache Point Observatory Galactic Evolution Experiment (APOGEE) Spectrographs
Abstract
We describe the design and performance of the near-infrared (1.51--1.70 micron), fiber-fed, multi-object (300 fibers), high resolution (R = lambda/delta lambda ~ 22,500) spectrograph built for the Apache Point Observatory Galactic Evolution Experiment (APOGEE). APOGEE is a survey of ~ 10^5 red giant stars that systematically sampled all Milky Way populations (bulge, disk, and halo) to study the Galaxy's chemical and kinematical history. It was part of the Sloan Digital Sky Survey III (SDSS-III) from 2011 -- 2014 using the 2.5 m Sloan Foundation Telescope at Apache Point Observatory, New Mexico. The APOGEE-2 survey is now using the spectrograph as part of SDSS-IV, as well as a second spectrograph, a close copy of the first, operating at the 2.5 m du Pont Telescope at Las Campanas Observatory in Chile. Although several fiber-fed, multi-object, high resolution spectrographs have been built for visual wavelength spectroscopy, the APOGEE spectrograph is one of the first such instruments built for observations in the near-infrared. The instrument's successful development was enabled by several key innovations, including a "gang connector" to allow simultaneous connections of 300 fibers; hermetically sealed feedthroughs to allow fibers to pass through the cryostat wall continuously; the first cryogenically deployed mosaic volume phase holographic grating; and a large refractive camera that includes mono-crystalline silicon and fused silica elements with diameters as large as ~ 400 mm. This paper contains a comprehensive description of all aspects of the instrument including the fiber system, optics and opto-mechanics, detector arrays, mechanics and cryogenics, instrument control, calibration system, optical performance and stability, lessons learned, and design changes for the second instrument.
Keywords
Cite
@article{arxiv.1902.00928,
title = {The Apache Point Observatory Galactic Evolution Experiment (APOGEE) Spectrographs},
author = {J. C. Wilson and F. R. Hearty and M. F. Skrutskie and S. R. Majewski and J. A. Holtzman and D. Eisenstein and J. Gunn and B. Blank and C. Henderson and S. Smee and M. Nelson and D. Nidever and J. Arns and R. Barkhouser and J. Barr and S. Beland and M. A. Bershady and M. R. Blanton and S. Brunner and A. Burton and L. Carey and M. Carr and J. P. Colque and J. Crane and G. J. Damke and J. W. Davidson and J. Dean and F. Di Mille and K. W. Don and G. Ebelke and M. Evans and G. Fitzgerald and B. Gillespie and M. Hall and A. Harding and P. Harding and R. Hammond and D. Hancock and C. Harrison and S. Hope and T. Horne and J. Karakla and C. Lam and F. Leger and N. MacDonald and P. Maseman and J. Matsunari and S. Melton and T. Mitcheltree and T. O'Brien and R. W. O'Connell and A. Patten and W. Richardson and G. Rieke and M. Rieke and A. Roman-Lopes and R. P. Schiavon and J. S. Sobeck and T. Stolberg and R. Stoll and M. Tembe and J. D. Trujillo and A. Uomoto and M. Vernieri and E. Walker and D. H. Weinberg and E. Young and B. Anthony-Brumfield and D. Bizyaev and B. Breslauer and N. De Lee and J. Downey and S. Halverson and J. Huehnerhoff and M. Klaene and E. Leon and D. Long and S. Mahadevan and E. Malanushenko and D. C. Nguyen and R. Owen and J. R. Sanchez-Gallego and C. Sayres and N. Shane and S. A. Shectman and M. Shetrone and D. Skinner and F. Stauffer and B. Zhao},
journal= {arXiv preprint arXiv:1902.00928},
year = {2019}
}
Comments
81 pages, 67 figures, PASP, accepted