Identifying Stellar Streams in Gaia DR2 with Data Mining Techniques
  Streams of stars from captured dwarf galaxies and dissolved globular clusters
are identifiable through the similarity of their orbital parameters, a fact
that remains true long after the streams have dispersed spatially. We calculate
the integrals of motion for 44855 stars, to a distance of 4 kpc from the Sun,
which have full and accurate 6D phase space positions in the Gaia DR2
catalogue. We then apply a novel combination of data mining, numerical and
statistical techniques to search for stellar streams. This process returns
seven high-confidence streams (including four that were not previously known),
all of which display tight clustering in the integral of motion space.
Colour-magnitude diagrams indicate that these streams are relatively simple,
old, metal-poor populations. A combined evaluation of the kinematics and
colour-magnitude properties suggests that the previously undiscovered streams
are fragments of the Gaia-Enceladus progenitor. The success of this project
demonstrates the usefulness of data mining techniques in exploring large
datasets.
