Models of cuspy triaxial stellar systems - I. Stability and chaoticity

We used the N-body code of Hernquist & Ostriker to build a dozen cuspy (γ ≃ 1) triaxial models of stellar systems through dissipationless collapses of initially spherical distributions of 10<SUP>6</SUP> particles. We chose four sets of initial conditions that resulted in models morph...

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Detalles Bibliográficos
Autores principales: Zorzi, Alejandra Francisca, Muzzio, Juan Carlos
Formato: Articulo
Lenguaje:Inglés
Publicado: 2012
Materias:
Acceso en línea:http://sedici.unlp.edu.ar/handle/10915/83972
Aporte de:
id I19-R120-10915-83972
record_format dspace
institution Universidad Nacional de La Plata
institution_str I-19
repository_str R-120
collection SEDICI (UNLP)
language Inglés
topic Ciencias Astronómicas
Chaos
Galaxies: elliptical and lenticular, cD
Galaxies: kinematics and dynamics
Methods: numerical
spellingShingle Ciencias Astronómicas
Chaos
Galaxies: elliptical and lenticular, cD
Galaxies: kinematics and dynamics
Methods: numerical
Zorzi, Alejandra Francisca
Muzzio, Juan Carlos
Models of cuspy triaxial stellar systems - I. Stability and chaoticity
topic_facet Ciencias Astronómicas
Chaos
Galaxies: elliptical and lenticular, cD
Galaxies: kinematics and dynamics
Methods: numerical
description We used the N-body code of Hernquist & Ostriker to build a dozen cuspy (γ ≃ 1) triaxial models of stellar systems through dissipationless collapses of initially spherical distributions of 10<SUP>6</SUP> particles. We chose four sets of initial conditions that resulted in models morphologically resembling E2, E3, E4 and E5 galaxies, respectively. Within each set, three different seed numbers were selected for the random number generator used to create the initial conditions, so that the three models of each set are statistically equivalent. We checked the stability of our models using the values of their central densities and of their moments of inertia, which turned out to be very constant indeed. The changes of those values were all less than 3 per cent over one Hubble time and, moreover, we show that the most likely cause of those changes are relaxation effects in the numerical code. We computed the six Lyapunov exponents of nearly 5000 orbits in each model in order to recognize regular, partially and fully chaotic orbits. All the models turned out to be highly chaotic, with less than 25 per cent of their orbits being regular. We conclude that it is quite possible to obtain cuspy triaxial stellar models that contain large fractions of chaotic orbits and are highly stable. The difficulty in building such models with the method of Schwarzschild should be attributed to the method itself and not to physical causes.
format Articulo
Articulo
author Zorzi, Alejandra Francisca
Muzzio, Juan Carlos
author_facet Zorzi, Alejandra Francisca
Muzzio, Juan Carlos
author_sort Zorzi, Alejandra Francisca
title Models of cuspy triaxial stellar systems - I. Stability and chaoticity
title_short Models of cuspy triaxial stellar systems - I. Stability and chaoticity
title_full Models of cuspy triaxial stellar systems - I. Stability and chaoticity
title_fullStr Models of cuspy triaxial stellar systems - I. Stability and chaoticity
title_full_unstemmed Models of cuspy triaxial stellar systems - I. Stability and chaoticity
title_sort models of cuspy triaxial stellar systems - i. stability and chaoticity
publishDate 2012
url http://sedici.unlp.edu.ar/handle/10915/83972
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AT muzziojuancarlos modelsofcuspytriaxialstellarsystemsistabilityandchaoticity
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