The black hole has been active for a short time

A new study shows that the black hole at the center of the Milky Way is a sleeping giant — but it’s been awake lately in cosmological terms.

Strasbourg – Sagittarius A* (Sgr A*), the supermassive black hole at the center of the Milky Way, has been dormant for a long time and has long failed to fuse material from its surroundings. Researchers know this because the black hole is much less luminous than other black holes at the centers of galaxies observed from Earth. But now a new study shows that the sleeping giant Sagittarius A* woke up about 200 years ago — not long ago in cosmological terms — to swallow gas and other cosmic matter around it.

to get this result, in the journal nature published A research team led by astronomer Frédéric Marin of the Strasbourg Observatory of the University of Strasbourg used the NASA IXPE Space Telescope. By measuring the direction and intensity of the electric field of the light waves, the telescope was pointed at the giant gas clouds near the black hole. Researchers there previously discovered that there should be bright X-ray fingerprints that should, in fact, be dark and cold.

The black hole at the center of the Milky Way has been active for 200 years

“One scenario as to why these giant molecular clouds glow so brightly is that they are actually an echo of an X-ray flash from long ago, indicating that our supermassive black hole wasn’t very quiet a few centuries ago,” explains lead author Marin. in one NASA ad.

To analyze the X-rays, the researchers combined the IXPE data with data from the Chandra and XMM-Newton space telescopes. This enabled them to isolate the X-ray signal and discover its source. “The polarization angle works like a compass, showing us the way to a mysterious light source that has long since disappeared,” explains Riccardo Ferrazoli, an astrophysicist at the Italian National Institute of Astrophysics. “And what lies in that direction? Nothing less than Sgr A*.”

Arc A* seemed to erupt briefly, consuming matter

As the search continued, the team found that X-rays from giant molecular clouds were reflecting light from a short, intense glow that originated in or near the black hole. Perhaps the reason for this is that the black hole suddenly swept away nearby matter. Based on the data, the research team assumes that the black hole at the center of the Milky Way was active for a short period of time about 200 years ago, at the beginning of the 19th century.

In the next step, the researchers want to repeat the observation and take more precise measurements. With the help of more data, one can estimate, among other things, more precisely when the black hole erupted and how intense the activity was. Studies of this kind help researchers gain new insights into the physical processes required to awaken Sgr A* from its sleep, explains IXPE scientist Stephen Eilert.

“We know that active galaxies and supermassive black holes can change on the human time scale,” Eilert confirms. “We are learning more about this galaxy’s behavior over time, its history of explosions, and we look forward to continuing to monitor it to identify changes that are typical and unique.” (unpaid bill)

Recently, researchers were able to capture a picture of a black hole spewing a jet of matter into space.