Recent observational constraints on the warm absorber in AGN Original Research Article

Among the most prominent observational signatures of the partly ionized component in active galactic nuclei (AGN), the so-called warm absorber, are spectral absorption features detected in the keV region. These features provide important diagnostics on the location and nature of the material surrounding the active nucleus. The Low Energy Concentrator Spectrometer (LECS) on board the BeppoSAX satellite operates in the range 0.1–10 keV. Because of its good low-energy resolution and effective area down to 0.1 keV it is a very efficient tool for the study of the complex spectral features due to warm absorbers, particularly when used in combination with the other narrow field instruments on BeppoSAX, sensitive at higher energies. We present here recent observations by BeppoSAX/LECS of the warm absorber in both a high luminosity radio quiet quasar and a Seyfert 1 galaxy.