Monte Carlo Simulations of the Clumpy Torus in Active Galactic Nuclei

Kemal Ramic

2012

It has been observed that approximately 10% to 30% of AGNs show no X-ray absorption, whereas the optical spectrum suggests signi cant obscuration. One possible explanation is that the obscuring medium consists of dense clumps. In the model, using Monte Carlo simulations, I conduct a study to check whether the clumpiness of the torus is a possible reason for the mismatch in optical and X-ray spectrums. For a variety of torus con gurations I have found that there is no mismatch in the number of the clumps intersected between the lines of sight originating in the X-ray and optical regions. If time variability is assumed I found that, due to clumpiness, it is not possible to change the spectrum of AGN galaxy from absorbed to unabsorbed, but clumps could be responsible for more mild variations in the spectra. If the X-ray and optical spectra are not simultaneously observed there exists some level of disagreement on the degree of obscuration.