Revolutionizing our View of Protostellar Multiplicity and Disks: The VLA Nascent Disk and Multiplicity (VANDAM) Survey of the Perseus Molecular Cloud

TL;DR

This survey used high-resolution VLA observations to uncover protostellar disks and multiple systems in the Perseus cloud, revealing new insights into star formation mechanisms and disk fragmentation.

Contribution

It provides the first unbiased, high-resolution survey of protostellar multiplicity and disks in Perseus, identifying new systems and substructures.

Findings

Detected 17 candidate protostellar disks, 12 in Class 0 stage.

Discovered 16 new multiple systems with separations < 500 AU.

Identified a bi-modal separation distribution indicating two formation mechanisms.

Abstract

There is substantial evidence for disk formation taking place during the early stages of star formation and for most stars being born in multiple systems; however, protostellar multiplicity and disk searches have been hampered by low resolution, sample bias, and variable sensitivity. We have conducted an unbiased, high-sensitivity Karl G. Jansky Very Large Array (VLA) survey toward all known protostars (n = 94) in the Perseus molecular cloud (d~230 pc), with a resolution of ~15 AU (0.06") at 8 mm. We have detected candidate protostellar disks toward 17 sources (with 12 of those in the Class 0 stage) and we have found substructure on < 50AU scales for three Class 0 disk candidates, possibly evidence for disk fragmentation. We have discovered 16 new multiple systems (or new components) in this survey; the new systems have separations < 500 AU and 3 by < 30 AU. We also found a bi-modal distribution of separations, with peaks at ~75 AU and ~3000 AU, suggestive of formation through two distinct mechanisms: disk and turbulent fragmentation. The results from this survey demonstrate the necessity and utility of uniform, unbiased surveys of protostellar systems at millimeter and centimeter wavelengths.