Recordatori [SEMINARI] Self-gravitating Tori around black holes and their instabilities

[Enric Marco]

Title: Self-gravitating Tori around black holes and their instabilities

by: Nikolaos Stergioulas

Aristotle University of Thessaloniki, Grècia

Seminari del departament d'Astronomia i Astrofísica

Dimecres 22 febrer 2012

15:00

Resum

We give an overview of recent progress in constructing equilibrium
models of self-gravitating tori around black holes, using a
self-consistent field method. We focus on the properties of models
with constant specific angular momentum that exactly fill their Roche
lobe and show that their angular momentum is limited in the same way
as in the case of a fixed background metric. Furthermore, we explore
the stability of such disks against runaway and nonaxisymmetric
instabilities using three-dimensional hydrodynamics simulations in
full general relativity. All of our models develop unstable
nonaxisymmetric modes on a dynamical time scale.We observe two
distinct types of instabilities: the Papaloizou-Pringle and the
so-called intermediate type instabilities. The development of the
nonaxisymmetric mode with azimuthal number m=1 is accompanied by an
outspiraling motion of the black hole, which significantly amplifies
the growth rate of the m=1 mode in some cases. We comment on the
generation of gravitational waves and on the development of the
runaway instability.
	
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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
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