Spectroscopic Survey on the Physical and Kinematical Structure of Active Galactic Nuclei
Abstract
We have reanalyzed the 900 ks Chandra X-ray spectrum of NGC 3783, finding evidence for asymmetry of the spectral absorption lines. The lines are fit with a parametric expression that results from an analytical treatment of radiatively driven winds (Lamers et al. 1987). The line asymmetry distribution derived from the spectrum is consistent with a non-spherical outflow with a finite optical depth. Within this scenario, our analytic model explains the observed correlations between the line velocity shifts and the ionization parameter and between the line velocity shift and the line asymmetry. This results provided a framework for detailed testing of models for the dynamic and physical properties of warm absorber in Seyfert galaxies. Further, we created detailed photoionization models (with the code XSTAR) where included Doppler wavelength shifts to the spectra formed throughout the gas flow, according to a predetermined density and velocity proper of a radiation driven wind. The treatment of radiation transfer was also changed in XSTAR in a way consistent with a moving flow. Our model was able to reproduce the observed correlation between the kinematics and the ionization of the absorption spectrum as well as the line asymmetries. To fit (kinematically speaking) the observation, the warm absorber requires two flows. One with high ionization parameters log xi ~ 3 - 1 which explain the formation of lines from Fe XXIII up to Si XIV, and another component with log xi ~ 2.2 - 0.1 responsible for the extended blue wings seen in the oxygen lines in the X-ray band. This picture establishes a clear relationship between the X-ray and UV absorbers in NGC 3783.
- Publication:
-
Ph.D. Thesis
- Pub Date:
- 2006
- Bibcode:
- 2006PhDT........23R
- Keywords:
-
- Chandra;
- X-Ray