The XMM-Newton view of the radio-loud narrow-line Seyfert 1 galaxy PMN J0948+0022

We analysed the archival XMM-Newton data of the radio-loud narrow-line Seyfert 1 galaxy PMN J0948+0022 in the energy range 0.3-10.0 keV. The X-ray data reveal that the spectrum in the 0.3-10.0 keV energy band is not a simple power law as previously described in the literature. Instead it consists of a power law with soft excess below 2.5 keV. The X-ray spectrum was fitted with four different models and it was shown the soft excess component of the spectrum in the 0.3-2.5 keV energy range could be described reasonably well within the framework of the thermal Comptonization model as well as relativistically blurred reflection model. The power-law component required to fit the spectrum beyond 2.5 keV was found to be rather hard compared to the ones observed in other unobscured active galactic nuclei. It is also shown that the Swift/X-Ray Telescope spectrum from the source could not reveal the soft excess component due to poor statistics. The fractional variability estimated from XMM-Newton data indicates the presence of independently varying components in the spectrum above and below 1 keV.