Zhang, YichenYichenZhangTan, Jonathan C.Jonathan C.TanSakai, NamiNamiSakaiTanaka, Kei E. I.Kei E. I.TanakaDe Buizer, James M.James M.De BuizerLiu, MengyaoMengyaoLiuBELTRAN SOROLLA, MARIA TERESAMARIA TERESABELTRAN SOROLLAKratter, KaitlinKaitlinKratterMardones, DiegoDiegoMardonesGaray, GuidoGuidoGaray2022-02-242022-02-2420190004-637Xhttp://hdl.handle.net/20.500.12386/31459We report molecular line observations of the massive protostellar source G339.88-1.26 with the Atacama Large Millimeter/Submillimeter Array. The observations reveal a highly collimated SiO jet extending from the 1.3 mm continuum source, which connects to a slightly wider but still highly collimated CO outflow. Rotational features perpendicular to the outflow axis are detected in various molecular emissions, including SiO, SO<SUB>2</SUB>, H<SUB>2</SUB>S, CH<SUB>3</SUB>OH, and H<SUB>2</SUB>CO emissions. Based on their spatial distributions and kinematics, we find that they trace different parts of the envelope-disk system. The SiO emission traces the disk and inner envelope in addition to the jet. The CH<SUB>3</SUB>OH and H<SUB>2</SUB>CO emissions mostly trace the infalling-rotating envelope and are enhanced around the transition region between envelope and disk, i.e., the centrifugal barrier. The SO<SUB>2</SUB> and H<SUB>2</SUB>S emissions are enhanced around the centrifugal barrier and also trace the outer part of the disk. Envelope kinematics are consistent with rotating-infalling motion, while those of the disk are consistent with Keplerian rotation. The radius and velocity of the centrifugal barrier are estimated to be about 530 au and 6 {km} {{{s}}}<SUP>-1</SUP>, respectively, leading to a central mass of about 11 M <SUB>☉</SUB>, consistent with estimates based on spectral energy distribution fitting. These results indicate that an ordered transition from an infalling-rotating envelope to a Keplerian disk through a centrifugal barrier, accompanied by changes of types of molecular line emissions, is a valid description of this massive protostellar source. This implies that at least some massive stars form in a similar way to low-mass stars via core accretion.STAMPAenArticle10.3847/1538-4357/ab0553https://iopscience.iop.org/article/10.3847/1538-4357/ab05532019ApJ...873...73ZFIS/05 - ASTRONOMIA E ASTROFISICA