RBS1423 - a new QSO with relativistic reflection from an ionised disk

Aims:We present the analysis and results of a 20 ks XMM-Newton observation of RBS1423.
Methods: X-ray spectral analysis is used to establish a significantly broadened relativistic iron Kα line from a highly ionised disk.
Results: A QSO at z = 2.262 was considered to be the optical counterpart of this ROSAT Bright Survey X-ray source. Based on the improved XMM-Newton source position we identified a z = 0.208 QSO as optical counterpart to RBS1423. The 0.2-12 keV X-ray luminosity of this radio-quiet QSO is 6 × 10⁴⁴ erg/s. The XMM-EPIC spectra are well described by a power law with a significantly broadened iron Kα line. Disk line models for both Schwarzschild and Kerr black holes require hydrogen-like iron ions to fit the measured line profile. Significant ionisation of the reflection disk is confirmed by model fits with ionised disk models, resulting in an ionisation parameter ξ ~ 2000.

Based on observations obtained

with XMM-Newton, an ESA science mission with instruments and contributions

directly funded by ESA Member States and NASA.