We present the latitude-normalized radial velocity ( v _ { b } ) distribution of 3318 subsolar metallicity , V \lesssim 13.5 stars from the Grid Giant Star Survey ( GGSS ) in Southern Hemisphere fields .
The sample includes giants mostly within \sim 5 kpc from the Galactic disks and halo .
The nearby halo is found to ( 1 ) exhibit significant kinematical substructure , and ( 2 ) be prominently represented by several velocity coherent structures , including a very retrograde “ cloud ” of stars at l \sim 285 ^ { \circ } and extended , retrograde “ streams ” visible as relatively tight l - v _ { b } sequences .
One sequence in the fourth Galactic quadrant lies within the l - v _ { b } space expected to contain tidal debris from the “ star cluster ” \omega Centauri .
Not only does \omega Cen lie precisely in this l - v _ { b } sequence , but the positions and v _ { b } of member stars match those of N -body simulations of tidally disrupting dwarf galaxies on orbits ending with \omega Cen ’ s current position and space motion .
But the ultimate proof that we have very likely found extended parts of the \omega Cen tidal stream comes from echelle spectroscopy of a subsample of the stars that reveals a very particular chemical abundance signature known to occur only in \omega Cen .
The newly discovered \omega Cen debris accounts for almost all fourth Galactic quadrant retrograde stars in the southern GGSS , which suggests \omega Cen is a dominant contributor of retrograde giant stars in the inner Galaxy .