Description of source "22506+5944" from Gomez-Ruiz et al. (2016)

Single-dish and interferometric CO observations of the outflow in Mol 151 were reported by Wu et al. (2005) and Su et al. (2004), respectively. The single-dish map shows a north– south outflow, while the interferometer map (including single-dish data for the zero spacing) shows an east–west outflow. In both cases, the total angular extent of the molecular emission is of order 1 arcmin. The driving source of the outflow(s) has been attributed to both IRAS 22506+5944 and to the near-IR source S4 (2MASS J22523871+6000445; e.g., Xu & Wang 2010).

The S4 position is nominally outside the IRAS error ellipse for 22506+5944. Nevertheless, we note that the 2MASS image shows a compact cluster of five sources that IRAS could not have resolved. We consider the IRAS source to correspond to the cluster, not to its individual members, and disregard the precise IRAS coordinates.

More importantly, we note that all six maser components that we detect are within 9″ of the S4 position (see Figure 7 of Su et al. 2004) while the two outflow lobes span 1′ in the east– west direction. Thus, as in several previous cases, the masers might trace the base of the outflow and not the terminus of the outflow lobes.