Star-forming galaxies across cosmic history with COMAP

The CO Mapping Array Pathfinder (COMAP) is opening a new window on the high-redshift universe by mapping star-forming galaxies through CO emission lines. By operating in the intensity mapping regime, COMAP can quickly and efficiently probe large volumes of space in three dimensions while retaining sensitivity to the faintest sources. Phase I of COMAP, which is currently being commissioned, will target the Epoch of Galaxy Assembly from redshift z = 2.4-3.4, and will allow measurement of the CO luminosity function in unprecedented detail. This can in turn constrain quantities such as the cosmic molecular gas abundance, or the star formation history, as well as provide many intriguing possibilities for cross-correlation. Phase II of the experiment will add significantly more sensitivity to this measurement and will add a lower-frequency receiver. This makes it possible to observe multiple CO lines from the Epoch of Reionization, offering a unique probe of the last great cosmic phase transition.