%0 Journal Article %T Lopsidedness of Self-consistent Galaxies Caused by the External Field Effect of Clusters %+ Institut d'Astrophysique de Paris (IAP) %A Wu, Xufen %A Wang, Yougang %A Feix, Martin %A Zhao, Hongsheng %< avec comité de lecture %@ 0004-637X %J The Astrophysical Journal %I American Astronomical Society %V 844 %8 2017 %D 2017 %Z 1706.07825 %Z 2017ApJ...844..130W %R 10.3847/1538-4357/aa7b8a %K galaxies: elliptical and lenticular %K cD %K galaxies: kinematics and dynamics %K gravitation %K methods: numerical %K Astrophysics - Astrophysics of Galaxies %Z Sciences of the Universe [physics] %Z Sciences of the Universe [physics]/Astrophysics [astro-ph]Journal articles %X Adopting Schwarzschild’s orbit-superposition technique, we construct a series of self-consistent galaxy models, embedded in the external field of galaxy clusters in the framework of Milgrom’s MOdified Newtonian Dynamics (MOND). These models represent relatively massive ellipticals with a Hernquist radial profile at various distances from the cluster center. Using N-body simulations, we perform a first analysis of these models and their evolution. We find that self-gravitating axisymmetric density models, even under a weak external field, lose their symmetry by instability and generally evolve to triaxial configurations. A kinematic analysis suggests that the instability originates from both box and nonclassified orbits with low angular momentum. We also consider a self-consistent isolated system that is then placed in a strong external field and allowed to evolve freely. This model, just like the corresponding equilibrium model in the same external field, eventually settles to a triaxial equilibrium as well, but has a higher velocity radial anisotropy and is rounder. The presence of an external field in the MOND universe generically predicts some lopsidedness of galaxy shapes. %G English %L insu-03747450 %U https://insu.hal.science/insu-03747450 %~ INSU %~ CNRS %~ IAP %~ SORBONNE-UNIVERSITE %~ SU-INF-2018 %~ SU-SCIENCES %~ SU-TI %~ ALLIANCE-SU