The Global Escape Velocity Profile and Virial Mass Estimate of The Milky Way Galaxy from Gaia Observations

TL;DR

This study uses Gaia data to determine the Milky Way's escape velocity profile and virial mass, revealing a Keplerian decline and a universal mass discrepancy-acceleration relation for cosmic objects.

Contribution

It provides the first comprehensive escape velocity profile from the Galactic center to satellites, linking local and global mass estimates with a universal relation.

Findings

Local escape velocity is ~700 km/s, higher than previous estimates.

The escape velocity profile follows an unbroken Keplerian decline.

A universal mass discrepancy-acceleration relation is identified.

Abstract

Gaia HyperVelocity Star (HVS) kinematic observations favor a local escape velocity of ~700 km/s, nearly forty-percent greater than conventional estimates. Combining HVS and dwarf galaxy satellite data reveal the global escape velocity profile for the Galaxy smoothly traces an unbroken Keplerian decline from the central bar to the most remote satellite galaxy. We reveal a robust upper bound in baryonic mass discrepancy (maximal relative accelerations) linked to the virial theorem and obtain a fundamental and universal mass discrepancy-acceleration relation for virialized compact cosmic objects.