2015ApJ...798L..33H

We present the results of continuum and ¹²CO(3-2) and CH₃OH(7-6) line observations of IRAS 16547-4247 made with the Atacama Large Millimeter/submillimeter Array (ALMA) at an angular resolution of ∼0.''5. The ¹²CO(3-2) emission shows two high-velocity outflows whose driving sources are located within the dust continuum peak. The alignment of these outflows does not coincide with that of the wide-angle, large-scale, bipolar outflow detected with the Atacama Pathfinder Experiment in previous studies. The CH₃OH(7-6) line emission traces an hourglass structure associated with the cavity walls created by the outflow lobes. Taking into account our results together with the position of the H₂ O and class I CH₃OH maser clusters, we discuss two possible scenarios that can explain the hourglass structure observed in IRAS 16547-4247: (1) precession of a biconical jet, (2) multiple, or at least two, driving sources powering intersecting outflows. Combining the available evidence, namely, the presence of two cross-aligned bipolar outflows and two different H₂ O maser groups, we suggest that IRAS 16547-4247 represents an early formation phase of a protocluster.