CU Boulder researchers have discovered a mechanism that explains the persistence of asymmetrical stellar clusters surrounding supermassive black holes in some galaxies and suggests that during post-galactic merger periods, orbiting stars could be flung into the black hole and destroyed at a rate of one per year.
The research, which was recently published in The Astrophysical Journal, also suggests an answer to a longstanding astronomical mystery about the behavior of eccentric stellar orbits near supermassive black holes and why the seemingly unstable dynamic survives long term.
A supermassive black hole’s gravity creates a nuclear star cluster surrounding it, which gravitational physics would expect to be spherically symmetric. However, several galaxies—including nearby Andromeda—have been observed with an asymmetrical star cluster that takes the form of a disk instead. Eccentric disks are suspected to be formed in the wake of a recent merger between two gas-rich galaxies.
Within the disk, each star follows an elliptical orbit that revolves around the supermassive black hole over time. The stars’ orbits nearly overlap and interact with each other frequently. Eventually, gravitational disruptions to one star’s orbit will bring it too close to the black hole.
Read more at University of Colorado at Boulder
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