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| EPoS Contribution |
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Kinematics and stability of high-mass protostellar disk candidates at subarcsecond resolution
Aida Ahmadi Leiden Obs, Leiden, NL | |
| There is growing consensus that the formation of high-mass stars proceeds through disk accretion, similar to that of lower mass stars. To this end, we have undertaken a large observational program (CORE) making use of interferometric observations from the NOrthern Extended Millimetre Array (NOEMA) for a sample of 20 high-mass protostellar objects in the 1.3 millimetre wavelength regime reaching ~0.4'' resolution (800 au at 2 kpc). We find rotational signatures in dense gas perpendicular to bipolar molecular outflows in most regions. Modelling the level populations of various rotational transitions of the dense gas tracer CH3CN, we find the disk candidates to be on average warm (~200 K). Studying the Toomre stability of the disk-like structures reveals that most high-mass young stellar objects are gravitationally unstable and prone to disk fragmentation. Since most high-mass stars are found to have companions, disk fragmentation seems to be an important mechanism by which such systems may be formed. In this talk, I will present our method which has been tested through synthetic observations of a high-resolution 3D radiation-hydrodynamic simulation and our findings from the CORE sample. | |
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| Caption: Intensity-weighted peak velocity (first moment) maps of CH3CN (12-11) K=3, showing the dense gas kinematics for 15 of the 20 sources in the CORE survey. The contours correspond to the 1.37 mm continuum. The blue and red arrows correspond to the estimated directions of bipolar blueshifted and redshifted molecular outflows, respectively. The dotted lines indicate the position of the strongest velocity gradient tracing the disk. The synthesised beam is shown in the bottom left corner and a scale bar in the bottom right corner of each panel. | |
| Collaborators: H. Beuther, MPIA, DE R. Kuiper, U Tuebingen, DE CORE Team |
Key publication
Suggested Session: High-Mass Star Formation |