AAS 199th meeting, Washington, DC, January 2002
Session 68. AGN
Oral, Tuesday, January 8, 2002, 10:00-11:30am, International Ballroom West

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[68.08] Advection-Dominated Accretion Flows with Outflow

T. Le, P. A. Becker (Center of Earth Observing and Space Research, and Department of Physics and Astronomy, George Mason University)

Observations have shown that relativistic jets are commonly associated with radio-loud Active Galatic Nuclei (AGNs). The original Advection-Dominated Accretion Flow (ADAF) model developed by Narayan & Yi has had some success in explaining the X-ray emission from Sgr~A* and several other AGNs that are underluminous in X-rays. However, the ADAF model does not include any mass loss from the accretion disk, and consequently it cannot account for the formation of relativistic outflows in the radio-loud sources. Some generalization of the original ADAF scenario is therefore required in order to explain the formation of the outflows. In this paper we develop a new ADAF/outflow scenario using the standard fluid conservation equations, modified to include the escape of mass, energy, and angular momentum from the disk due to the outflow. The model also includes a transport equation to simulate the acceleration of relativistic protons in the disk due to second-order Fermi acceleration in the shearing, turbulent magnetic field. The relativistic protons (and attendant electrons)escape from the disk to form the outflow, which starts as a hot wind and accelerates to reach a terminal Lorentz factor ~10, in agreement with observations of jets. We will discuss the results obtained and the significance for our understanding of underluminous black-hole accretion.

The author(s) of this abstract have provided an email address for comments about the abstract: tle@scs.gmu.edu

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