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Session 109 - Seyferts.
Oral session, Thursday, January 16
Piers 4/5,

[109.03] Universal Scattering Property of Seyfert Galaxies

C. R. Hall, F. C. Bruhweiler (The Catholic University of America), G. M. Madejski (Goddard/NASA)

The dusty torus model of Seyfert galaxies--the so-called Unified Model--(Antonucci amp; Miller 1985; Antonucci 1993) states that both type 1 and type 2 objects are intrinsically the same and share a similar overall geometry. Depending upon the observer's line of sight to the central engine, the broad lines which define the Seyfert type may be visible (Sy 1) or obscured by the torus (Sy 2), while the narrow lines are equally visible in both classes. In addition the polar regions of the torus contain an electron scattering atmosphere, extending beyond the polar openings. Via Thomson scattering of central engine photons, the broad line feature in Sy 2s can only be detected in polarized light.

>From an empirical analysis comparing the narrow Balmer H-beta observed in a sample of objects from both classes against the broad Balmer H-beta observed directly in Seyfert 1s, and observed in polarized light in Seyfert 2s, we find a general scattering law: the ratio of the intrinsic luminosity to the polarized luminosity in the line is approximately 300. This has strong implications on the geometry and physical properties of the scattering medium.


Antonucci, R.R.J. 1993,ARAamp;A, 31, 473 Antonucci, R.R.J.,amp; Miller,J.S. 1985,ApJ, 297, 621

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