Press Release

Massive Stars Moving around in Star Clusters

Massive Stars Moving around in Star Clusters

A research group at the University of Tokyo has performed a simulation of star cluster formation using a newly developed simulation code. The simulation revealed that some massive stars formed in the star cluster center were ejected to the outskirts of the cluster and ionized the molecular cloud there. These processes caused the formation of off-centered ionized bubbles seen in the Orion Nebula.

Simulated star cluster partially embedded in a cloud of hydrogen gas. (Credit: Michiko Fujii, Takaaki Takeda, 4D2U Project, National Astronomical Observatory of Japan)

In the simulation, the motions of stars in molecular clouds were accurately solved. The importance of the motions of massive stars in the formation phase of star clusters was for the first time shown using the new simulation. The simulation will be upgraded to simulations for up to 100 times more massive star clusters to understand the formation process of massive stars and star clusters.

These results appeared as Fujii et al. “SIRIUS Project. V. Formation of off-center ionized bubbles associated with Orion Nebula Cluster” in Monthly Notices of the Royal Astronomical Society on June, 8, 2022.

This research was supported by MEXT/JSPS KAKENHI Grant Number 19H01933, 21K03614, 20K14532, 21J00153, 21K03633, 21H04499, MEXT via the“Program for Promoting Researches on the Supercomputer Fugaku” (Toward a unified view of the universe: from large scale structures to planets), and JICFuS.

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Program for Promoting Researches on the Supercomputer Fugaku

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