• DOI:10.3847/1538-4357/ac63c7
• Corpus ID: 243985844

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

@article{Chung2021COMAPES,
  title={COMAP Early Science. V. Constraints and Forecasts at z ∼ 3},
  author={Dongwoo T. Chung and Patrick C. Breysse and Kieran A. Cleary and H{\aa}vard T. Ihle and Hamsa Padmanabhan and Marta B. Silva and J. Richard Bond and Jowita Borowska and Morgan Catha and Sarah E. Church and Delaney A. Dunne and Hans Kristian Eriksen and Marie Kristine Foss and Todd Gaier and Joshua Ott Gundersen and Stuart E. Harper and Andrew I. Harris and Brandon S. Hensley and Richard Hobbs and Laura C. Keating and Junhan Kim and James W. Lamb and Charles R. Lawrence and Jonas Gahr Sturtzel Lunde and Norman W. Murray and Timothy J. Pearson and Liju Philip and Maren Rasmussen and Anthony C. S. Readhead and Thomas J. Rennie and Nils-Ole Stutzer and Bade D. Uzgil and Marco P. Viero and Duncan J. Watts and Risa H. Wechsler and Ingunn Kathrine Wehus and David P. Woody},
  journal={The Astrophysical Journal},
  year={2021},
  volume={933}
}

• D. Chung, P. Breysse, +34 authors D. Woody
• Published 10 November 2021
• Physics
• The Astrophysical Journal

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, Tb2 ≲ 50 μK2, and the cosmic molecular gas density, ρ H2 < 2.5 × 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.