Misaligned Twin Molecular Outflows From Class-0 Proto-stellar Binary
  System VLA 1623A Unveiled by ALMA
  We present the results of ALMA observations toward the low-mass Class-0
binary system, VLA 1623Aab in the Ophiuchus molecular cloud in $^{12}$CO,
$^{13}$CO, and C$^{18}$O(2--1) lines. Our $^{12}$CO ($J$=2--1) data reveal that
the VLA 1623 outflow consists of twin spatially overlapped outflows/jets. The
redshifted northwestern jet exhibits the three cycles of wiggle with a spatial
period of 1360$\pm$10 au, corresponding to a time period of 180 yr. The
wiggle-like structure is also found in the position-velocity (PV) diagram,
showing an amplitude in velocity of about 0.9 km s$^{-1}$. Both the period and
the velocity amplitude of the wiggle are roughly consistent with those expected
from the binary parameters, i.e., the orbital period (460$\pm$20 yr) and the
Keplerian velocity (2.2 km s$^{-1}$). Our $^{13}$CO and C$^{18}$O images reveal
the nature of the dense gas in the two cm/mm sources, VLA 1623-B and -W, and
its relation to the outflows, and strongly support the previous interpretation
that both are shocked cloudlets. The driving sources of the twin molecular
outflows are, therefore, likely to be within the VLA 1623Aab binary. The axes
of the two molecular outflows are estimated to be inclined by 70$\arcdeg$ from
each other across the plane of sky, implying that the associated protostellar
disks are also misaligned by $70\arcdeg$. Such a misalignment, together with a
small binary separation of 34 au in the one of the youngest protobinary systems
known, is difficult to explain by models of disk fragmentation in quiescent
environments. Instead, other effects such as turbulence probably play roles in
misaligning the disks.
