Gaia DR2 in 6D: Searching for the fastest stars in the Galaxy

Understand

We search for the fastest stars in the subset of stars with radial velocity measurements of the second data release (DR2) of the European Space Agency mission Gaia.

• Starting from the observed positions, parallaxes, proper motions, and radial velocities, we construct the distance and total velocity distribution of more than $7$ million stars in our Milky Way, deriving the full 6D phase space information in Galactocentric coordinates.
• These information are shared in a catalogue, publicly available at http://home.strw.leidenuniv.nl/~marchetti/research.html.
• To search for unbound stars, we then focus on stars with a probability greater than $50 \%$ of being unbound from the Milky Way.