Recordatori [SEMINARI] Parallel, grid-adaptive simulations of relativistic jets

[Enric Marco]

Title: Parallel, grid-adaptive simulations of relativistic jets

by: Zakaria Meliani

from: Katholieke Universiteit Leuven, Bèlgica

Seminari del departament d'Astronomia i Astrofísica

Dijous 18 novembre 2010

12:00

Resum

The two types of Fanaroff-Riley radio loud galaxies, FRI and FRII, 
exhibit strong jets but with different properties. These differences may 
be associated to the central engine and/or the external medium. In this 
seminar I will present two models. I will start to discuss the dichotomy 
FRI/FRII accroding to the properties of the central engine, In this 
model we linked the AGN classification FRI and FRII to the transverse 
stratification of the jet. Indeed, theoretical arguments support this 
transverse stratification of jets with two components induced by 
intrinsic features of the central engine (accretion disk + black hole). 
We demonstrate that two-component jets with a relatively low kinetic 
energy flux contribution from the outer disk-jet are subject to the 
development of a relativistically enhanced, rotation-induced 
Rayleigh-Taylor type non-axisymmetric instability. This instability 
induces strong mixing between both components, decelerating the inner 
jet and leading to overall jet decollimation. In the second part, I will 
present the model that we proposed to explain HYbrid MOrphology Radio 
Sources (HYMORS), thereby invoking density discontinuities and variation 
in the initial open angle of jet. We explore how one-sided jet 
deceleration and a transition to FR I type can occur in HYMORS, which 
start as FR II (and remain so on the other side). The result of these 
work is that the FRII/FRI transition, can be associated to the central 
engine that induces transverse stratification of the jet and/or can be 
associated to the central engine (jet open angle) + external medium 
(density jump).

-- 
/------------------------------------\
 Dr. Enric Marco
 Departament d'Astronomia i Astrofísica
 Facultat de Física
 Universitat de València
 C/  Dr. Moliner, 50
 46100 Burjassot, Spain
 Phone: (34)-96-354-3069
 Fax:(34)-96-354-3084
 enric.marco en uv.es
 http://www.uv.es/marco
 http://www.uv.es/aulaastronomia
 http://www.uv.es/daa
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