Digging into the Interior of Hot Cores with ALMA (DIHCA). VII. Disk Candidates around High-mass Stars and Evidence of Anisotropic Infall

Abstract We study the kinematics of condensations in 30 fields forming high-mass stars with the Atacama Large Millimeter/submillimeter Array at a high resolution of ∼ 0 . ″ 08 on average (∼230 au). The presence of disks is important for feeding high-mass stars without feedback halting growth as their masses increase. In the search for velocity gradients resembling rotation that can reveal the presence of disks, we analyze the emission of gas tracers in 49 objects using CH 3 OH, CH 3 CN, and tentative detections of HNCO and cis-HCOOH. Most of the velocity distributions show velocity gradients indicative of rotation. We reveal a total of 32 disk candidates, the largest sample to date that has been uniformly analyzed at a few hundred astronomical unit scales in the high-mass regime. Their position–velocity maps are generally asymmetric with one side brighter than the opposite. We successfully fit a power law to the position–velocity maps of the disk candidates and find indices between −0.5 (Keplerian rotation) and −1 (rotation under specific angular momentum conservation) with a median of −0.7. Under Keplerian rotation assumption, we estimate central masses, uncorrected for inclination, ranging between 7 and 45 M ⊙ . Excluding outliers, the disk candidates are relatively more compact (