New Yale Study Says Wandering Black Holes Lurk in the Heart of the Milky Way
Despite our fascination with far-off galaxies and distant exoplanets, it turns out the humble Milky Way is still surprising astronomers with mind-blowing discoveries, like the super-precise star map the ESA just unveiled, or the possibility that the center of the galaxy is filled with thousands of black holes. If you thought that last one was a little concerning, a new study from Yale University claims that the Milky Way (and galaxies like it) may be host to invisible, wandering supermassive black holes.
Astronomers have known for a while that most galaxies have a supermassive black hole at their center (including the Milky Way), but the new study suggests that galaxies similar in mass to our own should actually have several SMBHs floating around.
Part of the study draws on data from a new computer simulation program called Romulus, which models the movements and behaviors of SMBHs. Where do these black holes come from? Collisions with other galaxies, says Yale astronomer Michael Tremmel.
"You can think of these black holes as 'failed' mergers between two supermassive black holes," Tremmel said.
"In some cases, after galaxies merge, their respective supermassive black holes will come together and merge themselves. In the case of these 'wanderers,' the smaller galaxy was destroyed by the larger galaxy in such a way as to leave its supermassive black hole far from the center of the larger galaxy where it will not be able to sink efficiently and merge with the central supermassive black hole."
Tremmel says it'd be extremely unlikely for a wandering black hole to come in contact with our solar system, but that doesn't mean they're not lurking somewhere in the Milky Way. The problem is, they're essentially invisible:
"I think the most direct line of future research on wandering black holes is to see how we might be able to infer their presence in our galaxy or other nearby massive galaxies (like Andromeda, for example)," he says. "They do not accrete gas, so they do not glow brightly like many of the black holes we are able to 'see.' "
If the infinite vastness of space didn't freak you out before, maybe the prospect of invisible black holes drifting around our galaxy will do the trick.