1101.1107 (Todd M. Tripp et al.)

The 21cm "Outer Arm" and the Outer-Galaxy High-Velocity Clouds: Connected by Kinematics, Metallicity, and Distance    [PDF]

Todd M. Tripp, Limin Song

Using high-resolution ultraviolet spectra obtained with the HST/Space Telescope Imaging Spectrograph (STIS) and the Far Ultraviolet Spectroscopic Explorer, we study the metallicity, kinematics, and distance of the gaseous "Outer Arm" (OA) and the high-velocity clouds (HVCs) in the outer Galaxy. We detect the OA in a variety of absorption lines toward two QSOs, H1821+643 and HS0624+6907. We search for OA absorption toward eight Galactic stars and detect it in one case, which constrains the OA Galactocentric radius to 9View original: http://arxiv.org/abs/1101.1107