June 23, 2023

The area surrounding Sagittarius A* (Image IXPE: NASA/MSFC/F. Marin et al; Chandra: NASA/CXC/SAO; Image Processing: L.Frattare, J.Major & K.Arcand)

An article published in the journal “Nature” reports evidence that about 200 years ago, Sagittarius A*, or simply Sgr A*, the supermassive black hole at the center of the Milky Way, had a period of intense activity during which it swallowed considerable amounts of gas and dust. A team of researchers led by Frédéric Marin of the Astronomical Observatory of Strasbourg, France, used in particular data collected by the IXPE space telescope to examine the polarization of X-ray light emitted by bright large molecular clouds close to Sgr A*. The conclusion is that their out-of-normal brightness must have been due to the fact that they are reflected emissions produced by some kind of powerful and short-lived flare of the supermassive black hole that occurred about 200 years ago.