An Ordered Envelope–Disk Transition in the Massive Protostellar Source G339.88-1.26
Tan, Jonathan C.
Tanaka, Kei E. I.
De Buizer, James M.
Beltrán, Maria T.
AffiliationUniv Arizona, Steward Observ
Univ Arizona, Dept Astron
KeywordsISM: individual objects (G339.88-1.26)
ISM: jets and outflows
ISM: kinematics and dynamics
MetadataShow full item record
PublisherIOP PUBLISHING LTD
CitationYichen Zhang et al 2019 ApJ 873 73
Rights© 2019. The American Astronomical Society.
Collection InformationThis item from the UA Faculty Publications collection is made available by the University of Arizona with support from the University of Arizona Libraries. If you have questions, please contact us at firstname.lastname@example.org.
AbstractWe 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, SO2, H2S, CH3OH, and H2CO 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 CH3OH and H2CO emissions mostly trace the infalling-rotating envelope and are enhanced around the transition region between envelope and disk, i.e., the centrifugal barrier. The SO2 and H2S 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(-1), respectively, leading to a central mass of about 11 M-circle dot, 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.
VersionFinal published version
SponsorsRIKEN Special Postdoctoral Researcher Program; NSF [AST1411527]; ERC [788829-MSTAR]; JSPS KAKENHI grant [18H05222]; NAOJ ALMA Scientific Research [2017-05A]; CONICYT [AFB-170002]