Preservation of Cuspy Profiles in Disk Galaxy Mergers

TL;DR

This study uses N-body simulations to investigate whether the cuspy dark matter profiles of galaxy mergers are preserved, finding that they remain intact across various mass ratios and initial conditions.

Contribution

It introduces self-consistent N-body simulations with stellar disks and halo angular momentum to examine dark matter profile preservation in galaxy mergers.

Findings

Cuspy dark matter profiles are preserved after mergers.

Preservation occurs across different mass ratios.

Initial halo properties influence the merger outcomes.

Abstract

We carried out three self-consistent $N$-body simulations of galaxy mergers, with a cuspy dark matter profile, in order to study if the inner dark density slope is preserved in the remnants. In these simulations the progenitors include both a stellar disk and an intrinsic angular momentum for the halos, unlike previous similar studies. The mass-ratios of progenitor galaxies are about 1:1, 1:3 and 1:10. We find that the initial cuspy density profile of the dark halos is preserved in the remnants for the cases considered here.