Two Portions of Sagittarius Stream in the LAMOST Complete Spectroscopic
  Survey of Pointing Area at Southern Galactic Cap
  We constructed a sample of 13,798 stars with $T\rm_{eff}$, log $g$, [Fe/H],
radial velocity, proper motions and parallaxes from LAMOST DR5 and Gaia DR2 in
the LAMOST Complete Spectroscopic Survey of Pointing Area (LaCoSSPAr) at the
Southern Galactic Cap consisting of areas A and B. Using the distributions in
both proper motions and radial velocity, we detected very significant
overdensities in these two areas. These substructures most likely are portions
of Sagittarius (Sgr) stream. With the Density-Based Spatial Clustering of
Applications with Noise (DBSCAN) algorithm, 220 candidates stream members were
identified. Based upon distance to the Sun and published models, 106 of these
stars are likely to be the members of the Sgr stream. The abundance pattern of
these members using [$\alpha$/Fe] from Xiang et al. were found to be similar to
Galactic field stars with [Fe/H] $<$ -1.5 and deficient to Milky Way
populations at similar metallicities with [Fe/H] $>$ -1.0. No vertical and only
small radial gradients in metallicity along the orbit of Sgr stream were found
in our Sgr stream candidates.
