Presentation #312.05 in the session Cosmology II.
Early science results from the CO Mapping Array Project (COMAP) have placed strong constraints on the clustering component of the CO(1-0) power spectrum at z~3, using line-intensity mapping (LIM) to open a new window into high-redshift galaxy formation and evolution. A detection of the power spectrum is forecast by the end of the nominal 5-year survey. In the meantime, techniques combining LIM data with other, more traditional catalogs may be able to improve on current constraints. In this talk, we will present the stacking of COMAP data on the positions of quasars from the BOSS catalog. We place a constraint on the stacked CO line luminosity that is consistent with the CO luminosity of individual quasars in this redshift range, and a constraint on the cosmic molecular gas density that is competitive with respect to other LIM experiments. We will also discuss prospects for improving these constraints with the full five-year COMAP dataset, and by stacking on HETDEX, a deep Lyman-α galaxy survey overlapping our fields.