A Study on the Spatial Distribution of Satellite Galaxies within Dark Matter Halos in an N-body Numerical Simulation

Abstract

We fitted the spatial distributions of the satellite galaxies in different dark matter halos obtained from an N-body numerical simulation with a triaxial ellipsoid, and then used the axial ratio of the fitting ellipsoid to measure the flatness of that distribution. By comparing the axial ratio distributions under different conditions, we analyzed the effects of different factors on the calculated result, such as the number of sample satellite galaxies, the selection method of sample satellite galaxies, and the normalization on the radial distribution of the sample, then we analyzed the correlation between the minor axis of the fitting ellipsoid and the orientation of the large scale structure where the dark matter halos exist. We found that whether the radial distribution of the sample is normalized will have a rather large influence on the result, and that the minor axis of the fitting ellipsoid of the halo in a large-scale filament structure more tends to be perpendicular to the direction of the filament structure, and the minor axis of the fitting ellipsoid of the halo in a large-scale sheet structure more tends to be parallel to the normal direction of the sheet structure.