The detection of an extended moving group near the galactic disk

A radial velocity survey (median velocity precision ∼1.0 km s −1 ) for 879 field stars in the direction (l, b)=(277°, 9°) has been undertaken with the bench-mounted spectrograph, ARGUS, and echelle grating at the CTIO 4.0 m telescope. The radial velocity histogram shows a marked overabundance of stars in the range 74,0-76.0 km s −1 . We observe 18 stars in this interval, whereas only five such stars (within our ∼1° field) are expected on the basis of the Institute for Advanced Study Galaxy Model. Monte Carlo simulations indicate that this feature is significant at better than the 99% level