Résumé / Abstract Seminaire_IAP
« Toward a Testable, Physics-Based Theory of Accretion Disk Spectra »

Omer Blaes
Dept. Physic Astronomy, Univ. California (Irvine, California, Etats-Unis d'Amérique)

For over 30 years, accretion disk models that make connection to observations have been based on the Shakura-Sunyaev alpha prescription for the anomalous stress. While such models have had some success, this approach is fundamentally incomplete because it does not, and cannot, address the physical effects of the true underlying angular momentum transport mechanism. Adopting the assumption that magnetorotational (MRI) turbulence dominates this mechanism, I will use recent simulation data to show how more reliable accretion disk models are now beginning to become possible. I will present results on disk spectra which incorporate the effects of MRI dissipation and dynamical support of the disk atmosphere by strong magnetic fields produced in the turbulence. I will also discuss theoretical progress in our understanding of the physical state of the inner, radiation pressure dominated zone of luminous accretion disks around black holes, focusing in particular on the roles of convective and photon bubble instabilities.
vendredi 4 novembre 2005 - 11:00
, Institut d'Astrophysique de Paris
Page web du séminaire / Seminar's webpage