An X-ray and Near-IR spectroscopic analysis of the ULIRG IRAS 05189-2524

We present new, quasi-simultaneous hard X-ray and near-IR spectra of the ultraluminous infrared galaxy IRAS 05189-2524, and discuss them together with archival and literature data. The 1.9 Seyfert nucleus is Compton-thin. The near-IR broad lines are seen in transmission, similarly to the X rays, and the medium along the line of sight has an Av/Nh ratio definitely lower than Galactic. The increase in obscuration observed at the latter epoch has (Delta Av)/(Delta Nh) also less than Galactic, supporting a correlation between the properties of the obscuring matter and its proximity to the center. The measured Av is compatible with the broad component of Halpha being seen in transmission, as opposed to scattering, so that most of the observed polarization must be due to dichroism. The bolometric luminosity of the AGN, deduced from the X-ray and line luminosities, falls definitely short of accounting for the IR luminosity of the galaxy, consistent with its coolish infrared color.