Does the existence of a plane of satellites constrain properties of the Milky Way?

TL;DR

This study investigates whether the presence of a satellite galaxy plane around the Milky Way constrains its properties, finding no strong correlations in simulations that would allow such inferences.

Contribution

It provides an analysis of satellite galaxy planes in cosmological simulations to assess their potential to constrain host galaxy properties.

Findings

No strong correlation between satellite plane properties and host halo characteristics.

The existence of the VPOS does not significantly constrain the Milky Way's properties.

Observational biases do not alter the lack of correlation found.

Abstract

According to the hierarchical model of galaxy formation underlying our current understanding of cosmology, the Milky Way (MW) has continued to accrete smaller-sized dwarf galaxies since its formation. Remnants of this process surround the MW as debris streams and satellite galaxies, and provide information that is complementary to studies of the Galaxy itself. The satellite system thus has the potential to teach us about the formation and evolution of the MW. Can the existence of a narrow, co-rotating plane of satellite galaxies (the Vast Polar Structure, VPOS) put constraints on our Galaxy's properties? Are such satellite galaxy planes more narrow around less massive hosts, more abundant around more concentrated hosts, more kinematically coherent around more early-forming halos? To address such questions, we have looked for correlations between properties of satellite galaxy planes fitted to cosmological simulations in the ELVIS suite and properties of their host dark matter halos, while accounting for realistic observational biases such as the obscuration by the disk of the MW. We find no evidence for strong correlations that would allow conclusions on the host halo properties from the mere existence of the VPOS around our Galaxy.