The text discusses the discovery of a vast swarm of black holes at the center of the Milky Way. The central few light years of the galaxy is believed to contain a swarm of smaller black holes that have infiltrated from the surrounding galaxy. This conclusion is based on a recent Nature paper by Haley Ettel titled "A Density Cusp of Quiescent X-ray Binaries in the Central Parsec of the Galaxy". The paper provides strong evidence that the core of our galaxy is packed with hundreds or possibly thousands of black holes.
The text explains the process of how black holes form and migrate towards the center of the Milky Way. The core of our galaxy is a supermassive black hole four million times the mass of our sun. It flings nearby stars into extreme slingshot orbits and consumes anything that gets too close, emitting blasts of X-rays.
The text also discusses how Haley and her team identified these black holes. They used the orbiting Chandra X-ray Observatory to hunt for quiescent X-ray binaries, which are X-ray binaries that are not actively gobbling up their companion stars. The team found 92 point-like X-ray sources within one parsec or around three light-years of the galactic center. After weeding out other astrophysical critters that also shine bright in X-rays, there remained 13 probable quiescent X-ray binaries, which appeared to be the type powered by black holes. The researchers extrapolated that there would need to be at least hundreds of stellar mass black holes in the central few light years to get these 13 X-ray binaries.
This result is significant for the new field of gravitational wave astronomy. The densely packed black holes in the centers of galaxies could provide clues to the source of gravitational waves detected by LIGO. The text also mentions that the sun would be inside the solar system's Oort cloud if it was near the galactic core. The nearest black hole would be inside the solar system.
The text concludes with a promotion for CuriosityStream, a subscription streaming service that offers documentaries and non-fiction titles from some of the world's best filmmakers.
1. The core of our galaxy contains a vast swarm of black holes.
2. The core of our galaxy is a wild place, with stars so densely packed that the night sky would be 500 times brighter than our own.
3. A supermassive black hole, four million times the mass of our sun, lurks in the center of the galaxy.
4. This black hole flings nearby stars into extreme slingshot orbits and consumes anything that gets too close.
5. The central few light years of the Milky Way is thought to contain a vast swarm of smaller black holes.
6. These smaller black holes have rained in from the surrounding galaxy.
7. The process of the black holes migrating towards the center of the Milky Way is called dynamical friction.
8. The process takes a really long time for a stellar mass black hole, over a few billion years.
9. Our galaxy is surrounded by globular clusters, ancient extremely dense mini galaxies containing millions of stars.
10. These globular clusters are much more massive than a single black hole and reach the galactic center a lot more quickly.
11. The black holes in the core of the galaxy are mostly detected through X-ray binaries, which are binary systems where a black hole or a neutron star is in a binary orbit with a companion star.
12. The researchers found 92 point-like X-ray sources within one parsec or around three light-years of the galactic center, which were potential X-ray binaries.
13. After weeding out other astrophysical critters, there remained 13 probable quiescent X-ray binaries which appeared to be the type powered by black holes.
14. The researchers extrapolated that there would need to be at least hundreds of stellar mass black holes in the central few light years in order to get these 13 X-ray binaries.
15. This indicates a swarm of black holes in the central few light years of the Milky Way's core.
16. This result is especially important for the new field of gravitational wave astronomy.
17. The nearest black hole to the sun would be inside the solar system's Oort cloud.
18. The result implies that the Milky Way's center is the craziest and most terrifying environment in nearby space.