A panoramic landscape of the Sagittarius stream in Gaia DR2 revealed
  with the STREAMFINDER spyglass
  We present the first full six-dimensional panoramic portrait of the
Sagittarius stream, obtained by searching for wide stellar streams in the Gaia
DR2 dataset with the STREAMFINDER algorithm. We use the kinematic behavior of
the sample to devise a selection of Gaia RR Lyrae, providing excellent distance
measurements along the stream. The proper motion data are complemented with
radial velocities from public surveys. We find that the global morphological
and kinematic properties of the Sagittarius stream are still reasonably well
reproduced by the simple Law & Majewski (2010) model (LM10), although the model
overestimates the leading arm and trailing arm distances by up to $\sim 15$%.
The sample newly reveals the leading arm of the Sagittarius stream as it passes
into very crowded regions of the Galactic disk towards the Galactic Anticenter
direction. Fortuitously, this part of the stream is almost exactly at the
diametrically opposite location from the Galactic Center to the progenitor,
which should allow an assessment of the influence of dynamical friction and
self-gravity in a way that is nearly independent of the underlying Galactic
potential model.
