Science Writing, (EFE).- The center of the Milky Way is a supermassive black hole, Sagittarius A*, which came out of its space lethargy 200 years ago to devour gas and other cosmic debris that was in its neighborhood.
The discovery, published this Wednesday by Nature, was made possible by data collected by NASA’s IXPE telescope, on which an international team headed by the University of Strasbourg (France) is based.
Sagittarius A* is estimated to be four million times more massive than the Sun, but it is much less luminous than the black holes in other galaxies observed to date, which would suggest that it has not actively absorbed material from its surroundings.
swallowed cosmic objects
However, the IXPE data suggest that this huge hole “woke up” at the beginning of the 19th century and swallowed cosmic objects that transited close enough to it for a year.
After this period of activity, Sagittarius A* returned to its state of tranquility, explained the French National Center for Scientific Research (CNRS).
recent x-ray emission
The astronomers used IXPE data that revealed a relatively recent X-ray emission from gigantic gas clouds in the vicinity of the hole.
Most of the comic clouds, called molecular clouds, are cold and dark, so their X-rays should be weak, but the one near Sagittarius A* shined brightly.
“It wasn’t so quiet a few centuries ago”
One hypothesis is that these gigantic molecular clouds were so bright because they echoed a flash of X-ray light from long ago, “indicating that our supermassive black hole was not so quiet a few centuries ago.” said study lead author Frédéric Marin, of the Strasbourg Astronomical Observatory.
The team discovered that the X-rays from the molecular clouds are actually reflected light produced by a short-lived intense glow originating in the vicinity of the supermassive black hole, probably caused by the accretion of some of the gas in those clouds by Sagittarius A*, indicates the Italian Space Agency (ASI)
The event occurred about 200 years ago
The IXPE data helped the researchers estimate the luminosity and duration of the original glow. The study suggests that the event occurred about 200 years ago or so, at the beginning of the 19th century,” said Steven Ehlert of NASA.
The team’s next goal is to repeat the observations and determine the physical mechanisms required for a black hole to transition from a state of “drowsiness” to one of activity.