Effects on the local dark matter distribution due to the large magellanic cloud

Abstract

ABSTRACT We study the local dark matter distribution in two models for the Milky Way (MW)-Large Magellanic Cloud (LMC) interaction. The effect of the LMC on the local dark matter distribution is dependent on the evolution of the MW-LMC system, such that a static model is insufficient to accurately model the dark matter velocity distribution in the solar neighbourhood. An evolved model boosts local LMC dark matter particle velocities by nearly 50 per cent, to a median value of ≈750 km s−1. MW dark matter particles also experience a velocity boost caused by disc reflex motion owing to the infall of the LMC. We study the implications of LMC particles in the solar neighbourhood for dark matter detection experiments. The directionality of LMC particles is distinguishable from the MW particles, with a difference in the apparent origin centroid location between the MW and LMC particles of 26 ± 6°. This unique identifier along with their high velocities can be utilized by directional detectors to search for dark matter particles originating in the LMC.