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Arthur T Knackerbracket has found the following story:

Though mighty, the Milky Way and galaxies of similar mass are not without scars chronicling turbulent histories. University of California, Irvine astronomers and others have shown that clusters of supernovas can cause the birth of scattered, eccentrically orbiting suns in outer stellar halos, upending commonly held notions of how star systems have formed and evolved over billions of years.

Hyper-realistic, cosmologically self-consistent computer simulations from the Feedback in Realistic Environments 2 project enabled the scientists to model the disruptions in otherwise orderly galactic rotations. The team's work is the subject of a study published today in the Monthly Notices of the Royal Astronomical Society.

"These highly accurate numerical simulations have shown us that it's likely the Milky Way has been launching stars in circumgalactic space in outflows triggered by supernova explosions," said senior author James Bullock, dean of UCI's School of Physical Sciences and a professor of physics & astronomy. "It's fascinating, because when multiple big stars die, the resulting energy can expel gas from the galaxy, which in turn cools, causing new stars to be born."

[...] The researchers said that while their conclusions have been drawn from simulations of galaxies forming, growing and evolving to the present day, there is actually a fair amount of observational evidence that stars are forming in outflows from galactic centers to their halos.

"In plots that compare data from the European Space Agency's Gaia mission—which provides a 3-D velocity chart of stars in the Milky Way—with other maps that show stellar density and metallicity, we can see structures similar to those produced by outflow stars in our simulations," Yu said.

Journal Reference
Yu, Sijie, Bullock, James S, Wetzel, Andrew, et al. Stars made in outflows may populate the stellar halo of the Milky Way, Monthly Notices of the Royal Astronomical Society (DOI: 10.1093/mnras/staa522)

Original Submission