Warm Absorbers in AGN - moderately photoionised outflow in active galactic nuclei

Séminaire IPAG de Susmita Chakravorty (IPAG), jeudi 11 décembre 2014 à 11h00, IPAG seminar room

Signatures of photoionised outflows are found in the high resolution soft X-ray spectra (.3 - 3 keV) of active galactic nuclei (AGN). Conventionally called the warm absorber (WA), they are still poorly understood, after 30 years of its discovery. We still do not know how dense this gas is and where it is located in the AGN system ! Understanding how these outflows are launched or how they impact feedback are important to understand some of the basic functioning of the active super-massive black holes. Through our analysis of the Chandra and HST spectra of the Quasar IRAS13349+2438, I shall discuss the methods and challenges of handling the data and deriving physical constraints. I shall further discuss the theory of thermodynamic stability conditions for photoionised gas and apply it to constrain the structure of the outflow in IRAS13349.