VLA and CARMA Observations of Protostars in the Cepheus Clouds:
  Sub-arcsecond Proto-Binaries Formed via Disk Fragmentation
  We present observations of three Class 0/I protostars (L1157-mm, CB230 IRS1,
and L1165-SMM1) using the Karl G. Jansky Very Large Array (VLA) and
observations of two (L1165-SMM1 and CB230 IRS1) with the Combined Array for
Research in Millimeter-wave Astronomy (CARMA). The VLA observations were taken
at wavelengths of $\lambda = 7.3$ mm, 1.4 cm, 3.3 cm, 4.0 cm, and 6.5 cm with a
best resolution of $\sim$0\farcs06 (18 AU) at 7.3 mm. The L1165-SMM1 CARMA
observations were taken at $\lambda = 1.3$ mm with a best resolution of
$\sim0\farcs3$ (100 AU), and the CB230 IRS1 observations were taken at $\lambda
= 3.4$ mm with a best resolution of $\sim$3\arcsec\ (900 AU). We find that
L1165-SMM1 and CB230 IRS1 have probable binary companions at separations of
$\sim$0\farcs3 (100 AU) from detections of secondary peaks at multiple
wavelengths. The position angles of these companions are nearly orthogonal to
the direction of the observed bipolar outflows, consistent with the expected
protostellar disk orientations. We suggest that these companions may have
formed from disk fragmentation; turbulent fragmentation would not
preferentially arrange the binary companions to be orthogonal to the outflow
direction. For L1165-SMM1, both the 7.3 mm and 1.3 mm emission show evidence of
a large (R $>$ 100 AU) disk. For the L1165-SMM1 primary protostar and the CB230
IRS1 secondary protostar, the 7.3 mm emission is resolved into structures
consistent with $\sim20$ AU radius disks. For the other protostars, including
L1157-mm, the emission is unresolved, suggesting disks with radii $< 20$ AU.
