The Turbulent Origin of Outflow and Spin Misalignment in Multiple Star Systems [SSA]

http://arxiv.org/abs/1606.08445


The protostellar outflows of wide-separation forming binaries frequently appear misaligned. We use magneto-hydrodynamic simulations to investigate the alignment of protostellar spin and molecular outflows for forming binary pairs. We show that the protostellar pairs, which form from turbulent fragmentation within a single parent core, have randomly oriented angular momenta. Although the pairs migrate to closer separations, their spins remain partially misaligned. We produce $^{12}$CO(2-1) synthetic observations of the simulations and characterize the outflow orientation in the emission maps. The CO-identified outflows exhibit a similar random distribution and are also statistically consistent with the observed distribution of molecular outflows. We conclude that observed misalignment provides a clear signature of binary formation via turbulent fragmentation. The persistence of misaligned outflows and stellar spins following dynamical evolution may provide a signature of binary origins for more evolved multiple star systems.

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S. Offner, M. Dunham, K. Lee, et. al.
Wed, 29 Jun 16
45/60

Comments: 6 pages, 4 figures, accepted to ApJL