Sulfur Chemistry in L1157-B1
  The main carrier of sulfur in dense clouds, where it is depleted from the gas
phase, remains a mystery. Shock waves in young molecular outflows disrupt the
ice mantles and allow us to directly probe the material that is ejected into
the gas phase. A comprehensive study of sulfur-bearing species towards
L1157-B1, a shocked region along a protostellar outflow, has been carried out
as part of the IRAM-30m large program ASAI. The dataset contains over 100 lines
of CCS, H$_2$CS, OCS, SO, SO$_2$ and isotopologues. The results of these
observations are presented, complementing previous studies of sulfur-bearing
species in the region. The column densities and fractional abundances of these
species are measured and together these species account for 10\% of the cosmic
sulfur abundance in the region. The gas properties derived from the
observations are also presented, demonstrating that sulfur bearing species
trace a wide range of different gas conditions in the region.
