Deconstructing the high-mass star-forming region IRAS 23033+5951

We report interferometric observations of the high-mass star-forming object IRAS 23033+5951. Our observations reveal two massive molecular cloud cores, designated IRAS 23033+5951-MMS1 and IRAS 23033+5951-MMS2. MMS1 has already formed a massive protostar and MMS2 appears to be on the verge of doing so. The latter core may be an example of a massive analog to a Class 0 star-forming object. The more evolved core shows some evidence of N2H+ destruction near the protostar, consistent with similar findings in low-mass star-forming objects. In addition to the already-known prominent HCO+ outflow, our SiO 2-1 and CH3OH 2-1 maps show evidence for two more candidate outflows, both presumably less powerful than the main one. Both cores are embedded in an elongated feature whose major axis is oriented almost exactly perpendicular to the axis of the most prominent outflow in the region. Although it has many of the characteristics of a disk, the 87,000AU(0.42 pc) diameter of this structure suggests that it is more likely to be the flattened, rotating remnant of the natal molecular cloud fragment from which the star-forming cores condensed. We conclude that IRAS 23033+5951 is an excellent example of massive star formation proceeding in relative isolation, perhaps by the method of monolithic collapse and disk accretion.