The mysterious supermassive black hole at the center of the Milky Way is currently putting on a spectacular cosmic fireworks show. The James Webb Space Telescope, operated by NASA, has observed the frenzied activities happening around this black hole, proving that this colossal entity is more active than scientists anticipated.
The Webb telescope was launched into space in 2021 and began collecting data in 2022, allowing astronomers to observe the supermassive black hole, known as Sagittarius A* (Sgr A*), for extended periods for the first time. Sgr A* has a mass of approximately 4.3 million times that of the Sun and is located about 26,000 light-years away from Earth.
Using the Webb telescope, scientists have discovered intense activity in the region surrounding Sgr A*, with it releasing flares. While some flares only last for a few seconds of faint flickering, Sgr A* erupts with brighter and more energetic flares on a daily basis. Some of the faintest flares can persist for months.
This study was published on Tuesday in the Astrophysical Journal Letters. Researchers observed a rotating gas disk (known as an accretion disk) around the black hole emitting continuous flashes of light, occasionally producing flares.
Farhad Yusef-Zadeh, the leader of the research team and an astrophysicist at Northwestern University in Illinois, stated, “The accretion disk is a very turbulent and chaotic region. When gas approaches the black hole under extreme gravity, it becomes even more chaotic and compressed.”
“Essentially, all supermassive black holes experience flares, but our black hole (referring to Sgr A*) is unique. It is always active, never seeming to reach a stable state. During the years 2023 and 2024, we conducted multiple observations of this black hole, noting its changes during each observation,” Yusef-Zadeh said in a statement.
“We see something different each time, which is truly extraordinary,” Yusef-Zadeh added.
The research team utilized the near-infrared camera (NIRCam) instrument on the Webb telescope to conduct multiple 8-10 hour observations of Sgr A* throughout the year, totaling 48 hours. This revealed the changes occurring around the black hole and its environment over time.
Yusef-Zadeh and colleagues anticipated seeing flares when observing the supermassive black hole at the center of the galaxy, but the results indicated that this black hole is even more active than expected. It continuously displays cosmic fireworks of varying brightness and durations. The accretion disk around the black hole generates five to six major flares per day, along with several minor flares or eruptions.
While the mechanisms behind these eruptions are similar to solar flares (which eject hot particles into space), they occur in a different astrophysical environment and at much higher energy levels.
These observations provide scientists with a deeper understanding of how black holes interact with their surroundings. Yusef-Zadeh noted that around 90% of the material in the accretion disk falls into the black hole, while the remaining material is ejected back into space.
Yusef-Zadeh and colleagues are still unsure of the processes that lead to these flares around this black hole. However, they suspect that flares of different durations are caused by different mechanisms.
Black holes are incredibly dense celestial objects, with gravity so immense that not even light can escape, making observing them quite challenging. Yusef-Zadeh expressed excitement for each observation of black hole activity.
(Reference: Space.com and Reuters)