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COMAP Early Science. II. Pathfinder Instrument

Lamb, James W. and Cleary, Kieran A. and Woody, David P. and Catha, Morgan and Chung, Dongwoo T. and Gundersen, Joshua Ott and Harper, Stuart E. and Harris, Andrew I. and Hobbs, Richard and Ihle, Håvard T. and Kocz, Jonathon and Pearson, Timothy J. and Philip, Liju and Powell, Travis W. and Basoalto, Lilian and Bond, J. Richard and Borowska, Jowita and Breysse, Patrick C. and Church, Sarah E. and Dickinson, Clive and Dunne, Delaney A. and Eriksen, Hans Kristian and Foss, Marie Kristine and Gaier, Todd and Kim, Junhan and Lawrence, Charles R. and Lunde, Jonas G. S. and Padmanabhan, Hamsa and Rasmussen, Maren and Readhead, Anthony C. S. and Reeves, Rodrigo and Rennie, Thomas J. and Stutzer, Nils-Ole and Viero, Marco P. and Watts, Duncan J. and Wehus, Ingunn Kathrine (2022) COMAP Early Science. II. Pathfinder Instrument. Astrophysical Journal, 933 (2). Art. No. 183. ISSN 0004-637X. doi:10.3847/1538-4357/ac63c6.

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Line intensity mapping (LIM) is a new technique for tracing the global properties of galaxies over cosmic time. Detection of the very faint signals from redshifted carbon monoxide (CO), a tracer of star formation, pushes the limits of what is feasible with a total-power instrument. The CO Mapping Project Pathfinder is a first-generation instrument aiming to prove the concept and develop the technology for future experiments, as well as delivering early science products. With 19 receiver channels in a hexagonal focal plane arrangement on a 10.4 m antenna and an instantaneous 26–34 GHz frequency range with 2 MHz resolution, it is ideally suited to measuring CO (J = 1–0) from z ∼ 3. In this paper we discuss strategies for designing and building the Pathfinder and the challenges that were encountered. The design of the instrument prioritized LIM requirements over those of ancillary science. After a couple of years of operation, the instrument is well understood, and the first year of data is already yielding useful science results. Experience with this Pathfinder will guide the design of the next generations of experiments.

Item Type:Article
Related URLs:
URLURL TypeDescription Paper
Lamb, James W.0000-0002-5959-1285
Cleary, Kieran A.0000-0002-8214-8265
Chung, Dongwoo T.0000-0003-2618-6504
Gundersen, Joshua Ott0000-0002-7524-4355
Harper, Stuart E.0000-0001-7911-5553
Harris, Andrew I.0000-0001-6159-9174
Ihle, Håvard T.0000-0003-3420-7766
Kocz, Jonathon0000-0003-0249-7586
Pearson, Timothy J.0000-0001-5213-6231
Philip, Liju0000-0001-7612-2379
Basoalto, Lilian0000-0002-2782-4937
Bond, J. Richard0000-0003-2358-9949
Breysse, Patrick C.0000-0001-8382-5275
Dickinson, Clive0000-0002-0045-442X
Dunne, Delaney A.0000-0002-5223-8315
Eriksen, Hans Kristian0000-0003-2332-5281
Foss, Marie Kristine0000-0001-8896-3159
Kim, Junhan0000-0002-4274-9373
Padmanabhan, Hamsa0000-0002-8800-5740
Readhead, Anthony C. S.0000-0001-9152-961X
Reeves, Rodrigo0000-0001-5704-271X
Rennie, Thomas J.0000-0002-1667-3897
Stutzer, Nils-Ole0000-0001-5301-1377
Viero, Marco P.0000-0003-0545-4872
Watts, Duncan J.0000-0002-5437-6121
Wehus, Ingunn Kathrine0000-0003-3821-7275
Additional Information:© 2022. The Author(s). Published by the American Astronomical Society. Original content from this work may be used under the terms of the Creative Commons Attribution 4.0 licence. Any further distribution of this work must maintain attribution to the author(s) and the title of the work, journal citation and DOI. Received 2021 November 24; accepted 2021 December 18; published 2022 July 13. Focus on Early Science Results from the CO Mapping Array Project (COMAP). This material is based on work supported by the National Science Foundation under grant Nos. 1517108, 1517288, 1517598, 1518282, and 1910999 and by the Keck Institute for Space Studies under "The First Billion Years: A Technical Development Program for Spectral Line Observations." Parts of the work were carried out at the Jet Propulsion Laboratory, California Institute of Technology, under a contract with the National Aeronautics and Space Administration, and funded through the internal Research and Technology Development program. D.T.C. is supported by a CITA/Dunlap Institute postdoctoral fellowship. The Dunlap Institute is funded through an endowment established by the David Dunlap family and the University of Toronto. C.D. and S.H. acknowledge support from an STFC Consolidated grant (ST/P000649/1). J.B., H.K.E., M.K.F., H.T.I., J.G.S.L., M.R., N.-O.S., D.W., and I.K.W. acknowledge support from the Research Council of Norway through grants 251328 and 274990 and from the European Research Council (ERC) under the Horizon 2020 Research and Innovation Program (grant agreement No. 819478, Cosmoglobe). J.G. acknowledges support from the University of Miami and is grateful to Hugh Medrano for assistance with cryostat design. L.K. was supported by the European Union's Horizon 2020 research and innovation program under the Marie Skłodowska-Curie grant agreement No. 885990. J. Kim is supported by a Robert A. Millikan Fellowship from Caltech. At JPL, we are grateful to Mary Soria for assembly work on the amplifier modules and to Jose Velasco, Ezra Long, and Jim Bowen for the use of their amplifier test facilities. H.P. acknowledges support from the Swiss National Science Foundation through Ambizione grant PZ00P2_179934. P.C.B. is supported by the James Arthur Postdoctoral Fellowship. R.R. acknowledges support from ANID-FONDECYT grant 1181620. M.V. acknowledges support from the Kavli Institute for Particle Astrophysics and Cosmology. We thank Isu Ravi for her contributions to the warm electronics and antenna drive characterization. We would also like to acknowledge the important contributions of Russell Keeney, Michael Virgin, and Andres Rizo for constructing and installing major mechanical parts of the instrument. We gratefully acknowledge hardware donations from Xilinx within the Xilinx University Program. Finally, we thank the anonymous referee for the careful reading of the manuscript.
Group:Astronomy Department, Keck Institute for Space Studies, Owens Valley Radio Observatory (OVRO)
Funding AgencyGrant Number
Keck Institute for Space Studies (KISS)UNSPECIFIED
JPL Research and Technology Development FundUNSPECIFIED
Canadian Institute for Theoretical AstrophysicsUNSPECIFIED
Dunlap Institute for Astronomy and AstrophysicsUNSPECIFIED
University of TorontoUNSPECIFIED
Science and Technology Facilities Council (STFC)ST/P000649/1
Research Council of Norway251328
Research Council of Norway274990
European Research Council (ERC)819478
University of MiamiUNSPECIFIED
Marie Curie Fellowship885990
Robert A. Millikan FellowshipUNSPECIFIED
Swiss National Science Foundation (SNSF)PZ00P2_179934
American Astronomical SocietyUNSPECIFIED
Fondo Nacional de Desarrollo Científico y Tecnológico (FONDECYT)1181620
Kavli Institute for Particle Astrophysics and CosmologyUNSPECIFIED
Subject Keywords:Astronomical instrumentation; Cassegrain telescopes; Galaxy clusters; Galaxy formation; High-redshift galaxy clusters; Molecular gas; Radio astronomy; Radio receivers; Radio telescopes
Issue or Number:2
Classification Code:Unified Astronomy Thesaurus concepts: Astronomical instrumentation (799); Cassegrain telescopes (202); Galaxy clusters (584); Galaxy formation (595); High-redshift galaxy clusters (2007); Molecular gas (1073); Radio astronomy (1338); Radio receivers
Record Number:CaltechAUTHORS:20220322-205032421
Persistent URL:
Official Citation:James W. Lamb et al 2022 ApJ 933 183
Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:113987
Deposited By: George Porter
Deposited On:23 Mar 2022 14:34
Last Modified:01 Aug 2022 20:22

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