AGN-driven outflows in the OH absorber galaxy IRAS 19154+2704

We present a two-dimensional study of the gas distribution, excitation, and kinematics of the OH absorber galaxy IRAS 19154+2704 using Gemini Multi-Object Spectrograph integral field unit observations. Its continuum image shows a disturbed morphology indicative of a past or ongoing interaction. The ionized gas emission presents two kinematic components: a narrow (sigma less than or similar to 300 km s(-1)) component that may be tracing the gas orbiting in the galaxy potential and a broad (sigma greater than or similar to 500 km s(-1)) component, which is produced by an active galactic nucleus (AGN)-driven outflow, with velocities reaching -500 km s(-1), which may exceed the escape velocity of the galaxy. The emission-line ratios and Baldwin-Phillips-Terlevich diagrams confirm that the gas excitation in the inner similar to 2 kpc is mainly due to the AGN, while in regions farther away, a contribution from star formation is observed. We estimate a mass-outflow rate of M(center dot)out=4.0 +/- 2.6 M-circle dot yr(-1) at a distance of 850 pc from the nucleus. The corresponding outflow kinetic power, E(center dot)out=(2.5 +/- 1.6) x 10(42) erg s(-1), is only 3 x 10(-4) L-bol (the AGN luminosity), but the large mass-outflow rate, if kept for an similar to 10 Myr AGN life cycle, will expel approximate to 10(8) M-circle dot in ionized gas alone. This is the sixth of a series of papers in which we have investigated the kinematics of ultra-luminous infrared galaxies, most of which are interacting galaxies showing OH megamasers. IRAS 19154 shows the strongest signatures of an active AGN, supporting an evolutionary scenario: interactions trigger AGN that fully appears in the most advanced stages of the interaction.