Disks around O-type young stellar objects
  Accretion disks are one of the key ingredients of the star formation process.
They redistribute angular momentum and, in the case of high-mass stars (M >
8Msun), disks would relieve the radiation pressure on the accreting material,
in particular in the equatorial direction, by beaming the radiation through the
poles of the system and this would allow the accretion to proceed onto the
central protostar (e.g., Tan et al. 2014 for a review on massive star
formation). In fact, in recent years, all high-mass star-forming theories
appear to converge to a disk-mediated accretion scenario (e.g., Krumholz et al.
2007; Kuiper et al. 2011; Bonnell & Bate 2006; Keto 2007) but do the
observations of high-mass young stellar objects (YSOs) confirm the theory
predictions? Or in other words, do true accretion disks around massive stars
really exist?
