Insanely bright light bursts from a black hole pair shock scientists

Astronomers have identified two giant black holes causing strange flashes of light at about one billion light years away from Earth. The flashes or light bursts are occurring at regular intervals, but what’s causing them is even more surprising.

The researchers suggest that the black hole pair is swirling within a vast cloud of gas, and their interaction with the gas cloud is actually sparking the unusual flashes —- marking it as the first observation of its kind.

“This is very different from anything I have seen before,” Lorena Hernández-García, lead researcher and a scientist at the Millennium Institute of Astrophysics (MAS) in Chile, told Space.com.

Surprisingly, the X-ray and UV light data formed as a result of the recurring light bursts reveal an M-shaped spectral pattern. “We are finding a lot of weird stuff that wasn’t possible to see before,” Hernández-García added.

The flashes confused scientists for three years

The astronomers received the first hint about the black hole flashes in March 2021. At that time, the Zwicky Transient Facility (ZTF) at the Palomar Observatory in California generated data that indicated the occurrence of some bright objects in the northern sky.

Researchers first believed it to be a supernova (a bright explosion resulting from the death of a star). However, when they noticed the event occurring repeatedly, they relabelled it as an active galactic nucleus (AGN), super-giant black holes found at the center of some galaxies. They are known to be extremely luminous as they emit large amounts of light.

However, when the researchers studied the M-shaped pattern formed as a result of spectral data received from observatories in Spain, India, and Mexico, they noticed the pattern was forming every two to three months. This behavior did not match a typical AGN, forcing them to rule out that explanation as well.

The patterns from the data also haven’t shown any signs of a tidal disruption event (TDE). Such an occurrence results in bright flashes of light from a star which is suddenly pulled apart by the intense gravity of a black hole.

“That’s when we said, ‘This is something interesting,” Hernández-García notes.

The only possibility that remains

The black hole pair is situated at the center of 2MASX J21240027+3409114, a galaxy that is about a billion lightyears away from the Milky Way. The black holes are currently located at a distance of 16 billion miles from each other.

The M-shaped spectral pattern suggests that they are probably in a space filled with gases and dust. Moreover, 2MASX, the galaxy in which they are located is also likely to merge with another neighboring galaxy. According to the researchers, the formation of giant gas clouds is a common phenomenon in merging galaxies.

Additionally, the spectral data indicate that the black hole pair has engulfed gas amounting to 1.5 to 2 solar masses (i.e. twice the mass of the Sun). Where did all this gas come from? All these factors suggest that the black holes are whirling in a massive gas cloud.

However, no advanced telescope or other piece of technology can observe such distant gas clouds. The study authors now hope to come across observations that could confirm this possibility.

The study is published in the journal Astronomy & Astrophysics.