Behavior of luminous matter in the head-on encounter of two ultralight BEC dark matter halos

TL;DR

This paper investigates the dynamics of ultralight BEC dark matter halos during head-on collisions, examining how different velocities affect their behavior and the distribution of luminous matter post-encounter.

Contribution

It introduces a combined simulation of BEC dark matter and luminous matter interactions during halo collisions, highlighting solitonic behavior and merger outcomes.

Findings

High velocity encounters show solitonic behavior of BEC halos.

Slow velocity collisions result in a merged single structure.

Post-collision luminous matter distribution varies with collision velocity.

Abstract

Within the context of ultralight BEC dark matter, we analyze the head-on encounters of two structures. These structures are made of a BEC component, which is a ground state equilibrium solution of the Gross-Pitaevskii-Poisson system, together with a component of luminous matter. The evolution of the Condensate dark matter is carried out by solving the time dependent GPP equations, whereas the luminous matter is modeled with particles interacting gravitationally on top of the BEC dark matter halos. We track the evolution of frontal encounters for various values of the collision velocity and analyze the regime of high velocity regime showing solitonic behavior of the BEC halos and that of slow velocities producing a single final structure. We measure the relative velocity of the dark matter with respect to the luminous matter after the encounters in the solitonic case and track the evolution of luminous matter in the case of merger.