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

[Enric Marco]

Parallel, grid-adaptive simulations of relativistic jets

Zakaria Meliani

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).
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/------------------------------------\
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
www.uv.es/marco
www.uv.es/aia2009
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