The Distance and Properties of Hydrogen Clouds in the Leading Arm of the
  Magellanic System
  We present a high-resolution study of five high-velocity clouds in the
Magellanic Leading Arm region. This is a follow-up study of our widefield
Parkes survey of the region in order to probe the multiphase structures of the
clouds and to give an insight to their origin, evolution and distance.
High-resolution data were obtained from the Australia Telescope Compact Array.
By combining with single-dish data from the Galactic All-Sky Survey (GASS), we
are able to probe compact and diffuse emission simultaneously. We identify
resolved and unresolved clumps. Physical parameters were derived for both
diffuse structure and compact clumps. The latter are cold with typical velocity
linewidths of 5 km/s. We find a gradient in thermal halo pressure, hydrogen
density and HI column density of HVC as a function of Galactic latitude. This
is possibly the first observational evidence of varying distance in the Leading
Arm region, with the leading part of the Leading Arm (LA II and III) probably
being closer to the Galactic disc than the trailing end (LA I).
