# Limit on the LMC mass from a census of its satellites

## TL;DR

This study uses satellite galaxy orbits to estimate the LMC's mass, finding it must be greater than 1.24×10^{11} solar masses, and explores the implications for satellite dynamics and group infall.

## Contribution

It introduces a new method to constrain the LMC's mass using satellite orbits and validates it with cosmological simulations, providing insights into satellite associations and dynamics.

## Key findings

- Six dwarfs likely accreted with the LMC, indicating group infall.
- Lower bound on LMC mass is > 1.24×10^{11} solar masses.
- LMC mass influences satellite orbital histories and sizes.

## Abstract

We study the orbits of ultra-faint dwarf galaxies in the combined presence of the Milky Way and LMC and we find 6 dwarfs which were likely accreted with the LMC (Car 2, Car 3, Hor 1, Hyi 1, Phe 2, Ret 2), in addition to the SMC, representing strong evidence of dwarf galaxy group infall. This procedure depends on the gravitational pull of the LMC, thus allowing us to place a lower bound on the Cloud's mass of $M_{\rm LMC} > 1.24\times10^{11} M_\odot$. This mass estimate is validated by applying the technique to a cosmological zoom-in simulation of a Milky Way-like galaxy with an LMC analogue where we find that while this lower bound may be overestimated, it will improve in the future with smaller observational errors. We apply this technique to dwarf galaxies lacking radial velocities and find that Eri 3 has a broad range of radial velocities for which it has a significant chance ($> 0.4$) of having being bound to the Cloud. We study the non-Magellanic classical satellites and find that Fornax has an appreciable probability of being an LMC satellite if the LMC is sufficiently massive. In addition, we explore how the orbits of the Milky Way satellites change in the presence of the LMC and find a significant change for several objects. Finally, we find that the LMC satellites are slightly smaller than the Milky Way satellites at a fixed luminosity, possibly due to the different tidal environments they have experienced.