Probing Cosmic Origins with CO and [C ii] Emission Lines

Primordial non-Gaussianity (PNG) is an invaluable window into the physical processes that gave rise to cosmological structure. The presence of local shape PNG imprints a distinct scale-dependent correction to the bias of dark matter tracers on large scales, which can be effectively probed via the technique of intensity mapping. Considering an upcoming generation of experiments, we demonstrate that intensity mapping of CO and [C ii] emission can improve upon the current best constraints from the Planck satellite. We show that measurement of the CO intensity power spectrum by a hypothetical next stage of the ground-based COMAP experiment can achieve $\sigma ({f}_{\mathrm{NL}}^{\mathrm{loc}})=3.4$ and that the proposed CMB satellite mission PIXIE can achieve $\sigma ({f}_{\mathrm{NL}}^{\mathrm{loc}})=3.9$ via measurement of the [C ii] intensity power spectrum.