A test of invariance of dark matter halo surface density using multiwavelength mock galaxy catalogues

Abstract

A large number of observations have shown that the dark matter halo surface density, given by the product of halo core radius and core density is nearly constant for a diverse suite of galaxies. Although this invariance of the halo surface density is violated at galaxy cluster and group scales, it is still an open question on whether the aforementioned constancy on galactic scales can be explained within $\Lambda$CDM. For this purpose, we probe the variation of halo surface density as a function of mass using multi-wavelength mock galaxy catalogs from $\Lambda$CDM simulations, where the adiabatic contraction of dark matter halos in the presence of baryons has been taken into account. We find that these baryonified $\Lambda$CDM halos were best fitted with a generalized-NFW profile, and the halo surface density from these halos has a degeneracy with respect to both the halo mass and the virial concentration. We find that the correlation with mass when averaged over concentration is consistent with a constant halo surface density. However, a power-law dependence as a function of halo mass also cannot be ruled out.