The Escape Velocity Profile of the Milky Way from Gaia DR3

Understand

The escape velocity profile of the Milky Way offers a crucial and independent measurement of its underlying mass distribution and dark matter properties.

• Using a sample of stars from Gaia DR3 with 6D kinematics and strict quality cuts, we obtain an escape velocity profile of the Milky Way from 4 kpc to 11 kpc in Galactocentric radius.
• To infer the escape velocity in radial bins, we model the tail of the stellar speed distribution with both traditional power law models and a new functional form that we introduce.
• While power law models tend to rely on extrapolation to high speeds, we find our new functional form gives the most faithful representation of the observed distribution.