Another X-ray UFO without a momentum-boosted molecular outflow. ALMA CO(1-0) observations of the galaxy pair IRAS 05054+1718

We present ALMA CO(1-0) observations of the nearby LIRG galaxy pair IRAS05054+1718 with a new analysis of X-ray data collected between 2012 and 2021 using NuSTAR, Swift, and XMM-Newton. The western component of the pair, NED01, hosts a Seyfert 1.9 nucleus launching a powerful X-ray UFO. Our X-ray spectral analysis suggests the UFO could be variable or multi-component in velocity and constrains its momentum flux to \(\dot p^{X-ray}_{out} \sim (4\pm2)\times 10^{34}\) gcms\(^{-2}\). ALMA CO(1-0) observations include also the eastern component of the pair, a LIRG with no clear evidence for an AGN. We study the CO(1-0) kinematics in the two galaxies using the 3D-BAROLO code. In both sources, we can model the bulk of the CO(1-0) emission with rotating disks and, after subtracting the best-fit models, we detect compact residual emission at S/N=15 within \(\sim3\)kpc from the centre. A molecular outflow in NED01, if present, cannot be brighter than such residuals, implying an upper limit on its outflow rate of \(\dot{M}^{mol}_{out} \lesssim 19\pm14~M_{\odot}~yr^{-1}\) and on its momentum rate of \(\dot p^{mol}_{out} \lesssim (2.7\pm2.4) \times 10^{34}\)gcms\(^{-1}\). Combined with the revised energetics of the X-ray wind, we derive an upper limit on the momentum rate ratio of \(\dot{p}^{mol}_{out}/\dot{p}^{X-ray}_{out}