Do the W44 and W28 molecular clouds show evidence of a shock

Abstract

OH and H I in the molecular cloud associated with W44 have been mapped, with 3 arcmin resolution. The optical depth maps support a cloud-remnant interaction. The line profiles show a multicomponent structure, which can explain increased line widths adjacent to the remnant without the necessity for shock processing. The OH and H I excitation temperatures are 13 K and 99 K. These values do not exclude the possibility of shock interaction. Observations of HCO(+), HCN, CS, N2H(+), OCS, and SO2 in W44 and W28 are presented. There are no abundance enhancements in these molecules, relative to CO. A broad-velocity component of HCO(+), HCN, and CS seen in the W28 cloud may represent shocked material. At present, there is no firm evidence to support shock processing of the molecular clouds adjacent to either remnant.