CfA astronomers Sarah Sadavoy and Mike Dunham were members of a team of astronomers that used the VLA and ALMA radio and millimeter-wave facilities to study seventeen protostellar systems of multiple stars in the nearby Perseus cloud. The sensitive observations were able to reveal the environments of the systems and determine the presence of any small-scale rotation or surrounding material. Twelve of the systems were spatially resolved, and eight showed dust emission structures surrounding the pair. The slightly more evolved systems in the set showed no evidence of circumbinary dust; they have probably reached the end point of their early evolution and finished accreting material. In summary, about two-thirds of the systems were consistent with the disk fragmentation theory and one-third were inconsistent with it. The results show that the disk fragmentation mechanism is an important one but probably not the whole story, and a larger sample should help constrain the processes even further. Reference: “The VLA/ALMA Nascent Disk and Multiplicity (VANDAM) Survey of Perseus Protostars. VI. Characterizing the Formation Mechanism for Close Multiple Systems,” John J. Tobin, Leslie W. Looney, Zhi-Yun Li, Sarah I. Sadavoy, Michael M. Dunham, Dominique Segura-Cox, Kaitlin Kratter, Claire J. Chandler, Carl Melis, Robert J. Harris, and Laura Perez, 29 October 2018, The Astrophysical Journal.DOI: 10.3847/1538-4357/aae1f7
