Date: Wednesday 01-Feb-2023
Time: 11:30-12:30 pm
Location: PSC 1136
Speaker: ChongChong He (UMD)
Title: "Zooming in 18 orders of magnitude: formation of large circumstellar disks in strongly magnetized cores"
Using a novel zoom-in adaptive-mesh-refinement method, I simulate the formation and fragmentation of prestellar cores in strongly magnetized giant molecular clouds (GMCs). The simulation simultaneously follow the evolution of a GMC, ~80 pc in size, and the formation of circumstellar disks with ~ AU resolution, achieving an unprecedented dynamic range of 18 orders of magnitude in volume, bridging the gap between clouds and individual protostars. I have shown that massive stars form from the filamentary collapse of dense cores and grow to masses several times bigger than the core mass due to accretion from larger scales via circumstellar disks, suggesting a competitive accretion scenario for high-mass star formation, a problem that is not well understood. Magnetic braking fails to prevent the formation of Keplerian disks even in cores with mass-to-flux ratios close to critical. I have shown that this is due to the extremely turbulent nature of the magnetic field which is many times weaker at braking disk rotation than in the perfectly aligned case, proposing a solution to the “magnetic braking catastrophe
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Past CTC Lunch seminars.
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Special accommodations for individuals with disabilities can be made by calling (301) 405-3001. It would be appreciated if we are notified at least one week in advance.
