An Ordered Envelope-Disk Transition in the Massive Protostellar Source G339.88-1.26
Artikel i vetenskaplig tidskrift, 2019

We 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 2 , H 2 S, CH 3 OH, and H 2 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 3 OH and H 2 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 2 and H 2 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 , respectively, leading to a central mass of about 11 M o , 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.

stars: massive

stars: formation

ISM: individual objects (G339.88-1.26)

ISM: jets and outflows

ISM: molecules

ISM: kinematics and dynamics

Författare

Yichen Zhang

RIKEN

Jonathan Tan

University of Virginia

Chalmers, Rymd-, geo- och miljövetenskap, Astronomi och plasmafysik, Galaktisk astrofysik

N. Sakai

RIKEN

Kei E.I. Tanaka

Osaka University

National Astronomical Observatory of Japan

James M. De Buizer

NASA Ames Research Center

Mengyao Liu

University of Virginia

M. T. Beltrán

Osservatorio Astrofisico di Arcetri

K. M. Kratter

University of Arizona

Diego Mardones

Universidad de Chile (UCH)

G. Garay

Universidad de Chile (UCH)

Astrophysical Journal

0004-637X (ISSN) 1538-4357 (eISSN)

Vol. 873 1 73

Ämneskategorier

Astronomi, astrofysik och kosmologi

Atom- och molekylfysik och optik

Fusion, plasma och rymdfysik

DOI

10.3847/1538-4357/ab0553

Mer information

Senast uppdaterat

2019-11-08