04/26/02
PORQUET Delphine Service d'Astrophysique (CEA-Saclay)
Orme des Merisiers (Bat. 709) SF2A- PNG- PNPS- PCHE-
91191 Gif-sur-Yvette, France
Presentation 1 : Oral
X-ray spectroscopy as a very powerful tool to the study of ionized me
Delphine Porquet & Jacques Dubau
We will present how the new generation of X-ray satellites, Chandra and XMM-Newton, brings us a wholly new understanding on the central region of Active Galactic Nuclei (AGNs). Particularly we will focus on sources exhibiting absorption and/or emission features due to ionized, circumnuclear gas along the line of sight, the so-called "Warm Absorber". We will show how fine X-ray spectroscopy and available accurate atomic data are crucial to infer most of the physical and geometrical parameters of "Warm Absorber" in different types of AGN: density, temperature, ionization process (photo-ionization and/or collisional ionization), ionization range (cold/warm/hot medium), column density, turbulent velocity, outflow or inflow velocity, etc. A statistical study of the physical parameters of the Warm Absorber is indeed essential to probe unified and/or evolution schemes in AGNs.