Physical conditions in the warped accretion disk of a massive star

Young massive stars warm up the large amount of gas and dust that condenses in their vicinity, exciting a forest lines from different molecular species. Their line brightness is diagnostic tool gas’s physical conditions locally, which we use to set constraints on environment where form. We made Atacama Large Millimeter/submillimeter Array at frequencies near 349 GHz, with an angular resolution 0′′.1, observe methyl cyanide (CH 3 CN) emission arises accretion disk young star. sample midplane twelve distinct beams, get independent measure (and dust’s) conditions. The extends above midplane, showing double-armed spiral morphology projected onto plane sky, ten additional beams: Along these apparent features, undergoes velocity gradients about 1 km s −1 per 2000 au. temperature ( T ) rises symmetrically along each side disk, 98 K 3000 au 289 250 au, following power law radius R −0.43 . CH CN column density N increases 9.2 × 10 15 cm −2 8.7 17 same radii, −1.8 In framework circular gaseous observed approximately edge-on, infer H 2 volume excess 4.8 ×10 9 −3 distance study stability against fragmentation methodology by Kratter et al. (2010, ApJ, 708, 1585), appropriate under rapid accretion, show marginally prone its whole extent.