2019MNRAS.489.1927S

We report the first Atacama large millimeter/submillimeter array observations of MCG-03-58-007, a local (z = 0.03236 ± 0.00002, this work) AGN (L_ AGN_∼10⁴⁵∼ erg∼s^–1), hosting a powerful X-ray ultrafast (v = 0.1c) outflow (UFO). The CO(1-0) line emission is observed across ∼18 kpc scales with a resolution of ∼1 kpc. About 78 per cent of the CO(1-0) luminosity traces a galaxy-size rotating disc. However, after subtracting the emission due to such rotating disc, we detect with a S/N = 20 a residual emission in the central ∼4 kpc. Such residuals may trace a low velocity (v_LOS = 170 km s^–1) outflow. We compare the momentum rate ({dot}P) and kinetic power ({dot}E) of such putative molecular outflow with that of the X-ray UFO and find {dot}P_ mol_/{dot}P_ UFO_∼0.4 and {dot}E_ mol_/{dot}E_ UFO_∼4×10^–3. This result is at odds with the energy-conserving scenario suggested by the large momentum boosts measured in some other molecular outflows. An alternative interpretation of the residual CO emission would be a compact rotating structure, distinct from the main disc, which would be a factor of ∼10-100 more extended and massive than typical circumnuclear discs revealed in Seyferts. In conclusion, in both scenarios, our results rule out the hypothesis of a momentum-boosted molecular outflow in this AGN, despite the presence of a powerful X-ray UFO.