A Caltech Library Service

COMAP Early Science. V. Constraints and Forecasts at z ∼ 3

Chung, Dongwoo T. and Breysse, Patrick C. and Cleary, Kieran A. and Ihle, Håvard T. and Padmanabhan, Hamsa and Silva, Marta B. and Bond, J. Richard and Borowska, Jowita and Catha, Morgan and Church, Sarah E. and Dunne, Delaney A. and Kristian Eriksen, Hans and Kristine Foss, Marie and Gaier, Todd and Gundersen, Joshua Ott and Harper, Stuart E. and Harris, Andrew I. and Hensley, Brandon and Hobbs, Richard and Keating, Laura C. and Kim, Junhan and Lamb, James W. and Lawrence, Charles R. and Lunde, Jonas Gahr Sturtzel and Murray, Norman and Pearson, Timothy J. and Philip, Liju and Rasmussen, Maren and Readhead, Anthony C. S. and Rennie, Thomas J. and Stutzer, Nils-Ole and Uzgil, Bade D. and Viero, Marco P. and Watts, Duncan J. and Wechsler, Risa H. and Kathrine Wehus, Ingunn and Woody, David P. (2022) COMAP Early Science. V. Constraints and Forecasts at z ∼ 3. Astrophysical Journal, 933 (2). Art. No. 186. ISSN 0004-637X. doi:10.3847/1538-4357/ac63c7.

[img] PDF - Published Version
Creative Commons Attribution.

[img] PDF - Accepted Version
See Usage Policy.


Use this Persistent URL to link to this item:


We present the current state of models for the z ∼ 3 carbon monoxide (CO) line intensity signal targeted by the CO Mapping Array Project (COMAP) Pathfinder in the context of its early science results. Our fiducial model, relating dark matter halo properties to CO luminosities, informs parameter priors with empirical models of the galaxy–halo connection and previous CO (1–0) observations. The Pathfinder early science data spanning wavenumbers k = 0.051–0.62 Mpc⁻¹ represent the first direct 3D constraint on the clustering component of the CO (1–0) power spectrum. Our 95% upper limit on the redshift-space clustering amplitude A_(clust) ≲ 70 μK² greatly improves on the indirect upper limit of 420 μK² reported from the CO Power Spectrum Survey (COPSS) measurement at k ∼ 1 Mpc⁻¹. The COMAP limit excludes a subset of models from previous literature and constrains interpretation of the COPSS results, demonstrating the complementary nature of COMAP and interferometric CO surveys. Using line bias expectations from our priors, we also constrain the squared mean line intensity–bias product, (T_b)₂ ≲ 50 μK², and the cosmic molecular gas density, ρ_(H2) < 2.5 x 10⁸ M_⊙ Mpc⁻³ (95% upper limits). Based on early instrument performance and our current CO signal estimates, we forecast that the 5 yr Pathfinder campaign will detect the CO power spectrum with overall signal-to-noise ratio of 9–17. Between then and now, we also expect to detect the CO–galaxy cross-spectrum using overlapping galaxy survey data, enabling enhanced inferences of cosmic star formation and galaxy evolution history.

Item Type:Article
Related URLs:
URLURL TypeDescription Paper
Chung, Dongwoo T.0000-0003-2618-6504
Breysse, Patrick C.0000-0001-8382-5275
Cleary, Kieran A.0000-0002-8214-8265
Ihle, Håvard T.0000-0003-3420-7766
Padmanabhan, Hamsa0000-0002-8800-5740
Silva, Marta B.0000-0003-0209-4816
Bond, J. Richard0000-0003-2358-9949
Dunne, Delaney A.0000-0002-5223-8315
Kristian Eriksen, Hans0000-0003-2332-5281
Kristine Foss, Marie0000-0001-8896-3159
Gundersen, Joshua Ott0000-0002-7524-4355
Harper, Stuart E.0000-0001-7911-5553
Harris, Andrew I.0000-0001-6159-9174
Hensley, Brandon0000-0001-7449-4638
Keating, Laura C.0000-0001-5211-1958
Kim, Junhan0000-0002-4274-9373
Lamb, James W.0000-0002-5959-1285
Pearson, Timothy J.0000-0001-5213-6231
Philip, Liju0000-0001-7612-2379
Readhead, Anthony C. S.0000-0001-9152-961X
Rennie, Thomas J.0000-0002-1667-3897
Stutzer, Nils-Ole0000-0001-5301-1377
Uzgil, Bade D.0000-0001-8526-3464
Viero, Marco P.0000-0003-0545-4872
Watts, Duncan J.0000-0002-5437-6121
Wechsler, Risa H.0000-0003-2229-011X
Kathrine Wehus, Ingunn0000-0003-3821-7275
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 19; revised 2022 February 24; accepted 2022 March 4; 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. 1518282, 1517108, 1517598, 1517288, and 1910999; by the Keck Institute for Space Studies under "The First Billion Years: A Technical Development Program for Spectral Line Observations"; and by a seed grant from the Kavli Institute for Particle Astrophysics and Cosmology. 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. The University of Toronto operates on the traditional land of the Huron-Wendat, the Seneca, and, most recently, the Mississaugas of the Credit River; D.T.C. is grateful to have the opportunity to work on this land. P.C.B. is supported by the James Arthur Postdoctoral Fellowship at New York University. K.C., J.W.L., A.C.S.R., B.D.U., and D.P.W. acknowledge support from NSF awards 1518282 and 1910999. Work at the University of Oslo is supported by 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). 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. H.P. acknowledges support from the Swiss National Science Foundation through Ambizione grant PZ00P2_179934. J.O.G. acknowledges support from the Keck Institute for Space Science, NSF AST-1517108, and the University of Miami. S.E.H. acknowledges support from an STFC Consolidated grant (ST/P000649/1). L.C.K. was supported by the European Union's Horizon 2020 research and innovation program under the Marie Skłodowska-Curie grant agreement No. 885990. J.K. is supported by a Robert A. Millikan Fellowship from Caltech. We thank Riccardo Pavesi for access to the COLDz ABC posterior sample used in this work. This research made use of NASA's Astrophysics Data System Bibliographic Services. Some of the computing for this project was performed on the Sherlock cluster. D.T.C. would like to thank Stanford University and the Stanford Research Computing Center for providing computational resources and support that contributed to these research results. The Scientific color maps acton and tokyo (Crameri 2021) are used in this study to prevent visual distortion of the data and exclusion of readers with color-vision deficiencies (Crameri et al. 2020). Finally, we would like to thank an anonymous referee whose comments and suggestions significantly improved this manuscript. Software: hmf (Murray et al. 2013); Matplotlib (Hunter 2007); (Foreman-Mackey 2016); Astropy, a community-developed core Python package for astronomy (Astropy Collaboration et al. 2013).
Group:Astronomy Department, Infrared Processing and Analysis Center (IPAC), Keck Institute for Space Studies, Owens Valley Radio Observatory (OVRO)
Funding AgencyGrant Number
Kavli Institute for Particle Astrophysics and CosmologyUNSPECIFIED
Canadian Institute for Theoretical AstrophysicsUNSPECIFIED
Dunlap Institute for Astronomy and AstrophysicsUNSPECIFIED
University of TorontoUNSPECIFIED
New York University (NYU)UNSPECIFIED
Research Council of Norway251328
Research Council of Norway274990
European Research Council (ERC)819478
JPL Research and Technology Development FundUNSPECIFIED
Swiss National Science Foundation (SNSF)PZ00P2_179934
University of MiamiUNSPECIFIED
Marie Curie Fellowship885990
Robert A. Millikan FellowshipUNSPECIFIED
Subject Keywords:CO line emission; Cosmological evolution; High-redshift galaxies; Molecular gas; Radio astronomy
Issue or Number:2
Classification Code:Unified Astronomy Thesaurus concepts: CO line emission (262); Cosmological evolution (336); High-redshift galaxies (734); Molecular gas (1073); Radio astronomy (1338)
Record Number:CaltechAUTHORS:20220722-769356000
Persistent URL:
Official Citation:Dongwoo T. Chung et al 2022 ApJ 933 186
Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:115794
Deposited By: George Porter
Deposited On:22 Jul 2022 21:33
Last Modified:22 Jul 2022 21:33

Repository Staff Only: item control page