Stellar Streams in the Gaia Era

Understand

The hierarchical model of galaxy formation predicts that the Milky Way halo is populated by tidal debris of dwarf galaxies and globular clusters.

• Due to long dynamical times, debris from the lowest mass objects remains coherent as thin and dynamically cold stellar streams for billions of years.
• The Gaia mission, providing astrometry and spectrophotometry for billions of stars, has brought three fundamental changes to our view of stellar streams in the Milky Way.
• First, more than a hundred stellar streams have been discovered and characterized using Gaia data.