2019ApJ...870L..19N

We report on a search for the [C II] 158 µm emission line from galaxies associated with four high-metallicity damped Lyα absorbers (DLAs) at z ∼ 4 using the Atacama Large Millimeter/submillimeter Array (ALMA). We detect [C II] 158 µm emission from galaxies at the DLA redshift in three fields, with one field showing two [C II] 158 µm emitters. Combined with previous results, we now have detected [C II] 158 µm emission from five of six galaxies associated with targeted high-metallicity DLAs at z ∼ 4. The galaxies have relatively large impact parameters, ≃16-45 kpc, [C II] 158 µm line luminosities of (0.36-30) x 10⁸ L_☉, and rest-frame far-infrared properties similar to those of luminous Lyman-break galaxies, with star formation rates of ≃7-110 M_☉ yr^–1. Comparing the absorption and emission line profiles yields a remarkable agreement between the line centroids, indicating that the DLA traces gas at velocities similar to that of the [C II] 158 µm emission. This disfavors a scenario where the DLA arises from gas in a companion galaxy. These observations highlight ALMA's unique ability to uncover a high-redshift galaxy population that has largely eluded detection for decades.