A candidate circumbinary Keplerian disk in G35.20–0.74 N: A study with ALMA

We report on ALMA observations of continuum and molecular line emission with 0."4 resolution towards the high-mass star-forming region G35.20–0.74 N. Two dense cores are detected in typical hot-core tracers (e.g., CH3CN) that reveal velocity gradients. In one of these cores, the velocity field can be fitted with an almost edge-on Keplerian disk rotating about a central mass of ~18 M⊙. This finding is consistent with the results of a recent study of the CO first overtone bandhead emission at 2.3 μm towards G35.20–0.74 N. The disk radius and mass are ≳2500 au and ~3 M⊙. To reconcile the observed bolometric luminosity (~3 × 104 L⊙) with the estimated stellar mass of 18 M⊙, we propose that the latter is the total mass of a binary system.