The Apache Point Observatory Galactic Evolution Experiment: First Detection of High-velocity Milky Way Bar Stars

Commissioning observations with the Apache Point Observatory GalacticEvolution Experiment (APOGEE), part of the Sloan Digital Sky Survey III,have produced radial velocities (RVs) for ~4700 K/M-giant stars in theMilky Way (MW) bulge. These high-resolution (R ~ 22, 500), high-S/N(>100 per resolution element), near-infrared (NIR; 1.51-1.70 μm)spectra provide accurate RVs (epsilon_V ~ 0.2 kms^-1) for the sample of stars in 18 Galactic bulge fieldsspanning -1° 20°, |b| 20°, and δ >-32°. This represents the largest NIR high-resolution spectroscopicsample of giant stars ever assembled in this region of the Galaxy. Acold (σ_V ~ 30 km s^-1), high-velocity peak (V_GSR ≈ +200 km s^-1) is found to comprise a