Astronomers used NASA’s Nuclear Spectroscopic Telescope Array (NuSTAR) telescope to discover nine large X-ray flares coming from Sagittarius A* (Sgr A*), the supermassive black hole at the center of the Milky Way.
These flares had previously gone unnoticed. Studying them provides insights into the environment near the black hole.
The researchers also discovered X-ray “echoes” coming from a giant molecular cloud near Sgr A* called “the Bridge.” The echoes are reflected X-ray light from past outbursts by the black hole.
Analyzing the echoes, which peaked in brightness in 2020, allowed the team to determine that around 200 years ago, Sgr A* experienced an outburst that made it over 100,000 times brighter in X-rays than it is now.
This research provides the first reconstruction of activity around Sgr A* over the past 24 years based on studying echoes off surrounding material.
It improves understanding of the behavior of our galaxy’s supermassive black hole and sheds light on mechanisms that can trigger X-ray flares even from quiet, non-feeding black holes like Sgr A*.
Source: Space
