Resolving M-dwarf Binaries in Young Moving Groups with Magellan Adaptive Optics

YMGs are benchmarks for the transition of stellar populations from their birth clusters to the field. We present data and analysis from our Magellan Adaptive Optics (MagAO) campaign to image more than 100 M-dwarf members of several YMGs in the southern sky, revealing ~30 previously unresolved visual stellar companions at separations of ~3 — 500 AU. Our study provides multiplicity statistics for young M-dwarfs in this intermediate regime of orbital distance. We combine our results with the SACY survey (Elliott et al. 2015), whose focus is on YMG systems with earlier type primaries, to provide an updated measurement of multiplicity as a function of stellar mass with significantly more statistical power at lower masses. Additionally, the tighter systems in our sample provide the opportunity for future monitoring and dynamical mass inference.