Escape probability methods versus ``exact" transfer for modelling the X-ray spectrum of Active Galactic Nuclei and X-ray binaries

  title={Escape probability methods versus ``exact" transfer for modelling the X-ray spectrum of Active Galactic Nuclei and X-ray binaries},
  author={A-M. Dumont and Suzy Collin and F. Paletou and S. Coup'e and Olivier Godet and Didier Pelat},
  journal={Astronomy and Astrophysics},
In the era of XMM-Newton and Chandra missions, it is crucial to use codes able to compute correctly the line spectrum of X-ray irradiated thick media (Thomson thickness of the order of unity), in order to build models for the structure and the emission of the central regions of Active Galactic Nuclei (AGN), or of X-ray binaries. In all photoionized codes except in our code Titan, the line intensities are computed with the so-called "escape probability approximation". In its last version, Titan… 
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