Kinematic Imprints of vortex-lines of BEC Dark Matter on Baryonic Matter

TL;DR

This study shows that vortex lines in Bose-Einstein Condensate Dark Matter can gravitationally influence baryonic matter, causing gas accumulation and forming observable ring-like structures that could serve as signatures of the dark matter model.

Contribution

It demonstrates the gravitational impact of vortex lines in BECDM on baryonic matter and identifies potential observable signatures in gas morphology.

Findings

Vortex lines induce gas condensation even without imposed symmetries.

Gas condensation is most efficient when baryonic matter dominates and has low initial velocity.

Vortex-driven gas structures can appear as persistent ring-like features in density maps.

Abstract

Our results demonstrate that vortex lines in Bose-Einstein Condensate Dark Matter (BECDM) can act as gravitational seeds that induce the condensation of baryonic matter, leading to localized gas accumulation even in the absence of imposed symmetries or rotation. Our analysis is based on the numerical solution of the system of equations for the BECDM gravitationally coupled to Euler equations for a compressible ideal gas (IG) that we use as a model of baryonic matter. Numerical simulations are constructed for various scenarios that start with a vortex solution for the BECDM and a randomly distributed ideal gas, with the aim of investigating whether the matter distribution and dynamics of the vortex influences the dynamics and distribution of the gas. We find that the gas condensation process is most efficient when the IG mass dominates over the BECDM, and when the IG has low initial velocity dispersion. We also find that strong bosonic self-interaction does not guarantee the vortex stability, instead, it can trigger dynamical instabilities that disrupt both the vortex structure and the surrounding gas. An interesting finding is that the vortex drives a persistent morphological signature on the gas, often in the form of ring-like features visible in projected density maps. These patterns survive nonlinear evolution and may serve as indirect tracers of vortex structures in BECDM halos, potentially offering a novel and testable observational probe of the model.