8th HEAD Meeting, 8-11 September, 2004
Session 26 AGN/Galactic Nuclei
Poster, Friday, September 10, 2004, 9:00am-10:00pm

[Previous] | [Session 26] | [Next]

[26.26] Evidence of Multiple Absorbing Structures around Seyfert Nuclei

J.M. Gelbord (MIT), K.A. Weaver (GSFC), T. Yaqoob (JHU)

We have examined every Seyfert galaxy in the ASCA archive, using X-ray spectral modeling to separate the absorption into high and low column density types (divided at NH ~ 1023 \mathrm{cm}-2). This classification is convenient because it can be robustly made even for low S/N data sets. Over 30 of these sources have resolved radio jets, allowing the relative alignment of the active nucleus and the host galactic axes to be constrained. We find a strong correlation between this internal alignment parameter and the column density. This relationship is inconsistent with the canonical Seyfert model having a single, parsec-scale obscuring torus, but can be explained if a second absorber is added to the picture. Our data suggest that the optical nuclei of Seyfert 2s can be obscured by either a parsec-scale, high-NH torus or a larger-scale, lower-NH absorber, the former aligning with the (randomly-oriented) nuclear region and the latter aligning with the plane of the host galaxy. We discuss this model and how it relates to other observational data.

This work was supported under NASA grant NCC5-447.

If you would like more information about this abstract, please follow the link to http://space.mit.edu/~jonathan/research.html. This link was provided by the author. When you follow it, you will leave the Web site for this meeting; to return, you should use the Back comand on your browser.

[Previous] | [Session 26] | [Next]

Bulletin of the American Astronomical Society, 36 #3
© 2004. The American Astronomical Soceity.