Theoretical Astrophysics Colloquia

51st Colloquium

Formation of Young Massive Clusters by Fast HI Gas Collision

Ryunosuke Maeda

Tohoku University


Abstract
We present simulations of the formation of young massive clusters (YMCs) through high-velocity collisions of HI gas in the Large Magellanic Cloud. The simulation models the magnetized interstellar gas dynamics, including the effects of self-gravity, heating/cooling, and stellar feedback. The results show that fast collisions of HI gas can form massive and compact gas clumps with masses of up to $10^5$ solar masses and radii of less than 10 pc. These clumps are gravitationally bound and have escape velocities greater than the sound speed of the ionized gas, which allows them to remain intact even after the onset of stellar feedback. The simulation also shows that fast collisions are essential for the formation of YMCs, as slow collisions do not produce enough dense gas to overcome the effects of stellar feedback. The findings suggest that YMCs can form in galaxy mergers and other environments where high-velocity collisions of HI gas occur.


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