A cluster of outflows in the Vulpecula Rift

TL;DR

This study reports on a newly observed cluster of outflows in the Vulpecula Rift, revealing high outflow efficiency, energetic flows capable of driving turbulence, and YSOs likely to grow into massive stars.

Contribution

First detailed analysis of outflows in the Vulpecula Rift showing high outflow-to-core mass ratio and implications for star formation processes.

Findings

Outflow-to-core mass ratio is approximately 0.4.

Outflows possess enough kinetic energy to drive turbulence and potentially unbind the region.

Detected SiO emission indicates active outflows, not fossil flows.

Abstract

We present $^{12}$CO, $^{13}$CO and C$^{18}$O (J=3$-$2) observations of a new cluster of outflows in the Vulpecula Rift with HARP-B on the JCMT. The mass associated with the outflows, measured using the $^{12}$CO HARP-B observations and assuming a distance to the region of 2.3 kpc, is 129 \msol{}, while the mass associated with the dense gas from C$^{18}$O observations is 458 \msol{} and the associated sub-millimeter core has a mass of 327 $\pm$ 112 \msol{} independently determined from Bolocam 1.1mm data. The outflow-to-core mass ratio is therefore $\sim$0.4, making this region one of the most efficient observed thus far with more than an order of magnitude more mass in the outflow than would be expected based on previous results. The kinetic energy associated with the flows, 94$\times10^{45}$ ergs, is enough to drive the turbulence in the local clump, and potentially unbind the local region altogether. The detection of SiO (J=8$-$7) emission toward the outflows indicates that the flow is still active, and not simply a fossil flow. We also model the SEDs of the four YSOs associated with the molecular material, finding them all to be of mid to early B spectral type. The energetic nature of the outflows and significant reservoir of cold dust detected in the sub-mm suggest that these intermediate mass YSOs will continue to accrete and become massive, rather than reach the main sequence at their current mass.