MULTI-WAVELENGTH ANALYSIS OF X-RAY SELECTED ACTIVE GALACTIC NUCLEI

Estelle Pons – LAM – Marseille

Central sources in galaxies are observed as active galactic nuclei (AGN) when its supermassive black hole (SMBH) grows through a phase of significant mass accretion. They span a wide range of wavelengths, emitting from the radio to the X-rays but all are driven by the same power which is the accretion of matter into the SMBH. X-ray observations provide the best way to study and identify AGN as host galaxy contamination is weak in this band, and X-rays are insensitive to absorption in contrast with optical observations. However, host galaxies contribution cannot be neglected in the identification of AGN, as in some cases they may hide the presence of their AGN in the optical/IR bands. Multi-wavelength observations represent the best way to decompose between host galaxy and AGN emission, through spectral energy distribution (SED) fitting. CIGALE is a powerful SED fitting code that can be used to decompose between the galaxy and AGN emissions, and it was recently improved in order to include the modelling of X-ray emission. The current AGN model of CIGALE only reproduce the continuum emission from the AGN. However, there are many prominent emission lines in the rest UV to IR spectrum of AGN, especially in broad line AGN,  and so can contribute to a large fraction of the flux observed in photometric bandpasses. I will present new results of the SED fitting of X-ray selected AGN, focusing on the possible contribution of the AGN emission lines in the photometric bands.