What is COMAP?

The CO Mapping Array Pathfinder (COMAP) is part of a program aiming to trace the spatial distribution of star-forming galaxies at the Epoch of Reionization (EoR).

Constraining the CO power spectrum from the EoR will ultimately require measurements at multiple frequencies and focal-plane arrays with hundreds of elements. As a first step towards this goal, Phase I of COMAP comprises a 10.4-m telescope, located at the Owens Valley Radio Observatory (OVRO), equipped with a 19-pixel spectrometer array that will map a total of 5 square degrees of sky in the frequency range 26-34 GHz, with spectral resolution R~800. This band will be sensitive to CO(1-0) in the redshift slice z=2.4-3.4 and to CO(2-1) in the redshift slice z = 5.8-7.8. A CASPER-based digital backend will process 8 GHz from each of the 19 pixels.

The aim of this pathfinder experiment is to i) demonstrate the feasibility and future potential of wide-field CO intensity mapping, and ii) provide a test-bed for the technology development and observational strategies. Phase I of COMAP will focus on constraining the CO power spectrum from the Epoch of Galaxy Assembly, at z=2.4-3.4.

June 2019: we are observing!

Phase I science operations have begun!

Latest COMAP Collaboration Publications

  • Chung+ 2019: "Cross-correlating Carbon Monoxide Line-intensity Maps with Spectroscopic and Photometric Galaxy Surveys"
  • Ihle+ 2019: "Joint Power Spectrum and Voxel Intensity Distribution Forecast on the CO Luminosity Function with COMAP"

COMAP Science & Instrument


Although the ultimate goal of COMAP is to target the EoR, Phase I will focus on the lower redshifts accessible to a Pathfinder-scale experiment: z = 2.4 - 3.4, at the peak of the cosmic star-formation rate density, during the Epoch of Galaxy Assembly.


COMAP Phase I is a single-dish experiment, using a 19-feed focal plane array operating at 26-34 GHz, deployed on a 10.4-m telescope at the Owens Valley Radio Observatory.