The Dark Matter Tidal Stripping History of the Sagittarius Core with N-body simulations

TL;DR

This study uses high-resolution N-body simulations to analyze the tidal stripping history of the Sagittarius dwarf galaxy's core, revealing significant dark matter loss and predicting complete disruption within 2 Gyr.

Contribution

It presents a detailed, high-resolution model of the Sagittarius core that reproduces observed properties without fine-tuning and predicts future disruption.

Findings

Dark matter was nearly entirely stripped after two pericenter passages.

The model reproduces observed morphology and kinematics of the Sgr core.

The Sgr core is predicted to be fully disrupted within 2 Gyr.

Abstract

The infall of the Sagittarius (Sgr) Dwarf Spheroidal Galaxy in the Milky Way halo is an unique opportunity to understand how the different components of a dwarf galaxy could be tidally removed. In this work, we reconstruct the Sgr core morphology and kinematics on the basis of a model that has already successfully reproduced the Sgr stream. Here we use a very high resolution model that almost resolves individual stars in the Sgr core. It reproduces most of the observed morphology and kinematic properties, without specific fine-tuning. We also show that the dark matter may have been almost entirely stripped by Milky Way tides after two passages at pericenter. Finally the model predicts that the Sgr core will be fully disrupted within the next 2 Gyr.