Galactic Halos in MONDian Cosmological Simulations

Abstract

In this paper a series of high-resolution n-body simulations is presented in which the equations of motion have been changed to account for MOdified Newtonian Dynamics (MOND). It is shown that a low-Omega0 MONDian model with an appropriate choice for the normalisation sigma8 can lead to similar clustering properties at redshift z=0 as the commonly accepted (standard) LCDM model. However, such a model shows no significant structures at high redshift with only very few objects present beyond z>3 that can be readily ascribed to the low Omega0 value adopted. The agreement with LCDM at redshift z=0 is driven by the more rapid structure evolution in MOND. Moreover, galaxy formation appears to be more strongly biased in MONDian cosmologies. Within the current implementation of MOND density profiles of gravitationally bound objects at z=0 can still be fitted by the universal NFW profile but MOND halos are less clumpy.