A ring of black holes or neutron stars has been discovered in a galaxy 300 million light years from Earth.
Astronomers used NASA’s Chandra X-ray Observatory and data reveals the presence of very bright X-ray sources, most likely binary systems powered by either a stellar-mass black hole or neutron star, in a remarkable ring.
X-rays from Chandra (purple) have been combined with optical data from NASA’s Hubble Space Telescope (red, green, and blue). Credit: Chandra X-ray Center
This ring, while not wielding power over Middle Earth, may help scientists better understand what happens when galaxies smash into one another in catastrophic impacts.
Where did the ring of black holes or neutron stars in AM 0644 come from?
Astronomers think that it was created when one galaxy was pulled into another galaxy by the force of gravity. The first galaxy generated ripples in the gas of the second galaxy, AM 0644, located in the lower right. These ripples then produced an expanding ring of gas in AM 0644 that triggered the birth of new stars. The first galaxy is possibly the one located in the lower left of the image.
The most massive of these fledgling stars will lead short lives – in cosmic terms – of millions of years. After that, their nuclear fuel is spent and the stars explode as supernovas leaving behind either black holes with masses typically between about five to twenty times that of the Sun, or neutron stars with a mass approximately equal to that of the Sun.
Some of these black holes or neutron stars have close companion stars, and siphon gas from their stellar partner. This gas falls towards the black hole or neutron star, forming a spinning disk like water circling a drain, and becomes heated by friction. This superheated gas produces large amounts of X-rays that Chandra can detect.