Left: HST (F814W) image of the ULIRG IRAS F08572+3915. The system is composed of a pair of interacting galaxies where the energetics are dominated by a buried AGN in the NW system (Rupke & Veilleux 2013a). The contours show continuum-subtracted CO(1-0) emission detected at a 3σ significance or above in the intensity maps integrated in the [−120,+120] km s⁻¹ (green) and [−400,+400] km s⁻¹ (purple) velocity range. The NOEMA synthesized beam (θ = 1.4″ × 1.13″) is illustrated in the bottom-left corner. The angular resolution achieved is a factor of ∼2 better than previous CO(1-0) observations (Cicone et al. 2014). Right: CO(1-0) spectra of the NW (top) and SE (bottom) galaxies extracted within the circular apertures shown in the left panel. This is the first time the SE component is detected in CO emission.