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SPHEREx: an all-sky NIR spectral survey

Korngut, Phillip M. and Bock, James J. and Akeson, Rachel and Capak, Peter and Doré, Olivier and Hemmati, Shoubaneh and Kirkpatrick, J. Davy and dePutter, Roland and Smith, Roger and Stickley, Nathaniel and Teplitz, Harry (2018) SPHEREx: an all-sky NIR spectral survey. In: Space Telescopes and Instrumentation 2018: Optical, Infrared, and Millimeter Wave. Proceedings of SPIE. No.10698. Society of Photo-Optical Instrumentation Engineers , Bellingham, WA, Art. No. 106981U. ISBN 9781510619494.

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SPHEREx, a mission in NASA’s Medium Explorer (MIDEX) program recently selected for Phase-A implementation, is an all-sky survey satellite that will produce a near-infrared spectrum for every 6 arcsecond pixel on the sky. SPHEREx has a simple, high-heritage design with large optical throughput to maximize spectral mapping speed. While the legacy data products will provide a rich archive of spectra for the entire astronomical community to mine, the instrument is optimized for three specific scientific goals: to probe inflation through the imprint primordial non-Gaussianity left on today’s large-scale cosmological structure; to survey the Galactic plane for water and other biogenic ices through absorption line studies; and to constrain the history of galaxy formation through power spectra of background fluctuations as measured in deep regions near the ecliptic poles. The aluminum telescope consists of a heavily baffled, wide-field off-axis reflective triplet design. The focal plane is imaged simultaneously by two mosaics of H2RG detector arrays separated by a dichroic beamsplitter. SPHEREx assembles spectra through the use of mass and volume efficient linear variable filters (LVFs) included in the focal plane assemblies, eliminating the need for any dispersive or moving elements. Instead, spectra are constructed through a series of small steps in the spacecraft attitude across the sky, modulating the location of an object within the FOV and varying the observation wavelength in each exposure. The spectra will cover the wavelength range between 0.75 and 5.0 µm at spectral resolutions ranging between R=35 and R=130. The entire telescope is cooled passively by a series of three V-groove radiators below 80K. An additional stage of radiative cooling is included to reduce the long wavelength focal plane temperature below 60K, controlling the dark current. As a whole, SPHEREx requires no new technologies and carries large technical and resource margins on every aspect of the design.

Item Type:Book Section
Related URLs:
URLURL TypeDescription Paper
Bock, James J.0000-0002-5710-5212
Akeson, Rachel0000-0001-9674-1564
Capak, Peter0000-0003-3578-6843
Doré, Olivier0000-0002-5009-7563
Hemmati, Shoubaneh0000-0003-2226-5395
Kirkpatrick, J. Davy0000-0003-4269-260X
Teplitz, Harry0000-0002-7064-5424
Alternate Title:Cosmology with the SPHEREX All-Sky Spectral Survey
Additional Information:© 2018 Society of Photo-Optical Instrumentation Engineers. We’d like to thank the contributors at L3-SSG, VIAVI, Sierra-Lobo and Photon Engineering, who helped develop this robust design. Chris Smith and Myrtle Lin were essential in the development of the FPA prototype. Part of the research described in this paper was carried out at the Jet Propulsion Laboratory, California Institute of Technology, under a contract with the National Aeronautics and Space Administration.
Group:Infrared Processing and Analysis Center (IPAC), Astronomy Department
Funding AgencyGrant Number
Subject Keywords:All Sky survey, linear variable filters, near infrared, cosmology, biogenic ices, extragalactic background light
Series Name:Proceedings of SPIE
Issue or Number:10698
Record Number:CaltechAUTHORS:20180814-144152671
Persistent URL:
Official Citation:Phillip M. Korngut, James J. Bock, Rachel Akeson, Matthew Ashby, Lindsey Bleem, Justin Boland, Douglas Bolton, Samuel Bradford, David Braun, Sean Bryan, Peter Capak, Tzu-Ching Chang, Andrew Coffey, Asantha Cooray, Brendan Crill, Olivier Doré, Tim Eifler, Chang Feng, Salman Habib, Katrin Heitmann, Shoubaneh Hemmati, Christopher Hirata, Woong-Seob Jeong, Minjin Kim, Davy Kirkpatrick, Theresa Kowalkowski, Elisabeth Krause, Carey Lisse, Philip Mauskopf, Daniel Masters, James McGuire, Gary Melnick, Hein Nguyen, Hooshang Nayyeri, Karin Oberg, Roland dePutter, William Purcell, Jennifer Rocca, Marcus Runyan, Karin Sandstrom, Roger Smith, Yong-Seon Song, Nathaniel Stickley, Jeremy Stober, Sara Susca, Harry Teplitz, Volker Tolls, Stephen Unwin, Michael Werner, Rogier Windhorst, Michael Zemcov, "SPHEREx: an all-sky NIR spectral survey", Proc. SPIE 10698, Space Telescopes and Instrumentation 2018: Optical, Infrared, and Millimeter Wave, 106981U (6 July 2018); doi: 10.1117/12.2312860;
Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:88799
Deposited By: Tony Diaz
Deposited On:15 Aug 2018 14:08
Last Modified:16 Nov 2021 00:29

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