Open AccessCan MOND take a bullet? Analytical comparisons of three versions of MOND beyond spherical symmetry
Author(s) -
Angus G. W.,
Famaey B.,
Zhao H. S.
Publication year - 2006
Publication title -
monthly notices of the royal astronomical society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.058
H-Index - 383
eISSN - 1365-2966
pISSN - 0035-8711
DOI - 10.1111/j.1365-2966.2006.10668.x
Subject(s) - physics , modified newtonian dynamics , dark matter , circular symmetry , galaxy , astrophysics , gravitation , gravitational lens , classical mechanics , theoretical physics , galaxy formation and evolution , galaxy rotation curve , redshift
A proper test of modified Newtonian dynamics (MOND) in systems of non‐trivial geometries depends on modelling subtle differences in several versions of its postulated theories. This is especially true for lensing and dynamics of barely virialized galaxy clusters with typical gravity of scale a 0 . The original MOND formula, the classical single‐field modification of the Poisson equation, and the multifield general relativistic theory of Bekenstein (tensor–vector–scalar, TeVeS) all lead to different predictions as we stray from spherical symmetry. In this paper, we study a class of analytical MONDian models for a system with a semi‐Hernquist baryonic profile. After presenting the analytical distribution function of the baryons in spherical limits, we develop orbits and gravitational lensing of the models in non‐spherical geometries. In particular, we can generate a multicentred baryonic system with a weak lensing signal resembling that of the merging galaxy cluster 1E 0657−56 with a bullet‐like light distribution. We finally present analytical scale‐free highly non‐spherical models to show the subtle differences between the single‐field classical MOND theory and the multifield TeVeS theory.