We present a multiplicity study of all known protostars ( 94 ) in the Perseus molecular cloud from a Karl G. Jansky Very Large Array ( VLA ) survey at Ka-band ( 8 mm and 1 cm ) and C-band ( 4 cm and 6.6 cm ) .
The observed sample has a bolometric luminosity range between 0.1 L _ { \sun } and \sim 33 L _ { \sun } , with a median of 0.7 L _ { \sun } .
This multiplicity study is based on the Ka-band data , having a best resolution of \sim 0 \farcs 065 ( 15 AU ) and separations out to \sim 43″ ( 10000 AU ) can be probed .
The overall multiplicity fraction ( MF ) is found to be of 0.40 \pm 0.06 and the companion star fraction ( CSF ) is 0.71 \pm 0.06 .
The MF and CSF of the Class 0 protostars are 0.57 \pm 0.09 and 1.2 \pm 0.2 , and the MF and CSF of Class I protostars are both 0.23 \pm 0.08 .
The distribution of companion separations appears bi-modal , with a peak at \sim 75 AU and another peak at \sim 3000 AU .
Turbulent fragmentation is likely the dominant mechanism on > 1000 AU scales and disk fragmentation is likely to be the dominant mechanism on < 200 AU scales .
Toward three Class 0 sources we find companions separated by < 30 AU .
These systems have the smallest separations of currently known Class 0 protostellar binary systems .
Moreover , these close systems are embedded within larger ( 50 AU to 400 AU ) structures and may be candidates for ongoing disk fragmentation .