Demos Kazanas, GSFC
Accretion Disk MHD Winds and the Blazar Sequence
We propose that the so called blazar sequence can be reproduced in terms of MHD winds off the accretion disks that feed the blazar black hole. The fundamental structure of this model is a 2D extended (size $\sim 1$ pc) disk MHD wind with density profile $n(r, \theta) \propto n_0(r_0/r)exp(-\theta/\theta_0) ~ (\theta_0 \simeq 10$ degrees), obtained by solving the 2D MHD equations, which: (a) Plays the role of the `molecular torus' invoked in AGN unification. (b) It provides a dynamically well defined geometric structure within which the relativistic jet propagates. We calculate the radiation field within the wind region that results from both electron scattering the AGN continuum radiation and its reprocessing into lines. Using this radiation field we can model the resulting Fermi LAT spectra as a function of the wind mass outflow rate $\dot m$ and the observer's inclination angle $\theta$. We find that low values of the mass flow rate the spectra are consistent with those of BL Lacs while converting to those of FSRQs for larger values of this parameter, thereby relating the Fermi LAT spectra to the underlying global AGN structure.

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