An Unusual System of HI Filaments near WR 5 and HD 17603

Abstract

We report the discovery of a system of unusual HI filaments which appear to be associated with molecular clouds in the Perseus spiral arm of our Galaxy. We investigate the hypothesis that this system is the result of a directed flow of dissociated gas from clouds trapped within an extended wind flow from massive stars. The Wolf-Rayet star WR 5 and the OIb(f) star HD 17603 are identified as candidate driving sources. However, an examination of this hypothesis within the context of the theory of mass-loaded winds shows that these two stars alone cannot account for the energetics and kinematics of the required spherically symmetric wind flow. Unless the apparent association between HI, molecular gas, and stars is an accidental one, we suggest that other as-yet unidentified stars must have contributed to driving the filaments.