On the nature of HESS J1503-582 revealed by the H.E.S.S. experiment:   Coincidence with a FVW?
  The H.E.S.S. survey of the inner Galaxy in the very-high-energy gamma-ray domain has led to the discovery of many extended sources, some of which do not appear to be associated with any obvious counterpart at traditional wavelengths (radio, infrared and X-ray). In this contribution, preliminary H.E.S.S. results on one of these so-called "dark" sources, namely HESS J1503-582, are presented. After introducing the properties of this source candidate, results of the search for counterparts in several astronomical windows are shown. Finally, its possible association with a "Forbidden-Velocity-Wing", a characteristic 21 cm HI line structure that appears as a deviation from the canonical Galactic rotation curve, is discussed. 
M. Renaud (MPI-K, Heidelberg, Germany), P. Goret (CEA/DSM/IRFU/SAp,   Saclay, France) and R.C.G. Chaves (MPI-K, Heidelberg, ...