Milky Way's graveyard of dead stars found

[Still Waters]

The first map of the "galactic underworld"—a chart of the corpses of once massive suns that have since collapsed into black holes and neutron stars—has revealed a graveyard that stretches three times the height of the Milky Way, and that almost a third of the objects have been flung out from the galaxy altogether.

"These compact remnants of dead stars show a fundamentally different distribution and structure to the visible galaxy," said David Sweeney, a Ph.D. student at the Sydney Institute for Astronomy at the University of Sydney, and lead author of the paper in the latest issue of Monthly Notices of the Royal Astronomical Society.

"The 'height' of the galactic underworld is over three times larger in the Milky Way itself," he added. "And an amazing 30 percent of objects have been completely ejected from the galaxy."

https://phys.org/news/2022-09-milky-graveyard-dead-stars.html

https://academic.oup.com/mnras/advance-article-abstract/doi/10.1093/mnras/stac2092/6675835?

[Piney]

They were probably chucked out during mergers in the early history of the galaxy.