Description
ABSTRACT
PKS 1345 + 12 is both an Ultraluminous infrared galaxy (ULIRG) and a young radio galaxy at z = 0.122, representing a late-stage major merger in the early phase of AGN activity. We present a spatially resolved analysis of the ionized gas outflow in the young radio source. Using VLT/MUSE integral field spectroscopy: Spectra were extracted in concentric annuli centered on the nucleus, enabling a radial resolved study of the emission-line properties. Multicomponent Gaussian fitting of the Hβ and [O III] emission lines reveals the presence of narrow, intermediate, and broad kinematic components, with the broadest component (FWHM ≳ 2800 km s⁻¹) tracing a high-velocity outflow. Using the luminosity of the broad Hβ component and electron densities derived from the [S II] doublet ratio, we estimate the mass of the gas and compute the mass outflow rate as a function of radius. We find that the outflow is not characterized by a single value, but instead exhibits a pronounced radial dependence: the mass outflow rate rises from the nuclear region (0 - 0.3 arcsec = ~3.90M☉/yr), and declines at larger distances. This behaviour indicates a non-uniform, evolving outflow structure. The derived outflow kinetic power (< 0.5% of the AGN bolometric luminosity) and momentum boost (< 1) suggest that the feedback from the young radio jet is not yet dominant. Our results highlight the importance of spatially resolved spectroscopy, and we caution that integrated measurements may overestimate mass outflow rates and kinetic energies and misrepresent the true properties of galactic outflows.