Evidence for Relativistic Disk Reflection in the Seyfert 1h Galaxy/ULIRG IRAS 05189-2524 Observed by NuSTAR and XMM-Newton

We present a spectral analysis of the NuSTAR and XMM-Newton observations of the Seyfert 1h galaxy/ULIRG IRAS 05189-2524 taken in 2013. We find evidence for relativistic disk reflection in the broadband X-ray spectrum: a highly asymmetric broad Fe Kα emission line extending down to 3 keV and a Compton scattering component above 10 keV. Physical modeling with a self-consistent disk reflection model suggests that the accretion disk is viewed at an intermediate angle with a supersolar iron abundance, and a mild constraint can be put on the high-energy cutoff of the power-law continuum. We test the disk reflection modeling under different absorption scenarios. A rapid black hole spin is favored; however, we cannot place a model-independent tight constraint on the value. The high reflection fraction ({R}_{ref} ≃ 2.0-3.2) suggests that the coronal illuminating source is compact and close to the black hole (lying within 8.7 {R}_{{g}} above the central black hole), where light-bending effects are important.