Captured, in X-rays, the signature of the awakening of two giant black holes: they dwell in the center of two galaxies previously considered inactive.
This is what emerges from the study published in the journal Nature by the German Max Planck Institute for Extraterrestrial Physics (Mpe).
Among the authors also the Italian Gabriele Ponti, of the National Institute of Astrophysics (INAF) in Milan.
The study will help astrophysicists better understand the activity of black holes in low-mass galaxies.
The result was obtained thanks to the observations of the eRosita X-ray space telescope, managed by the Mpe institute.
The central regions of galaxies that host black holes of mass millions or billions of times the Sun, also called quasars or active galactic nuclei, are so bright that they are considered by experts of the lighthouses of the distant universe.
“The nuclei of the two galaxies - explain the German astrophysicists - emit powerful glows in X-rays every few hours, reaching peaks of brightness comparable to those produced by a galaxy like the Milky Way.
This pulsating behavior - they conclude - could be due to a star or a celestial object of similar mass, which orbits one of the giant black holes in the central regions of the two galaxies ”.