A previously inactive supermassive black hole at the centre of the galaxy SDSS1335+0728, located around 300 million light-years away, has started producing intense X-ray flares. The phenomenon signals the start of its active phase.
The black hole’s eruptions, known as quasiperiodic eruptions, occur at fairly consistent intervals. These short-lived flares suggest the black hole has begun accreting material from its surroundings.
The central region of the galaxy, now classified as an active galactic nucleus (AGN), has been named "Ansky" by the research team. Its sudden activation was first recorded in late 2019.
According to researchers, Ansky’s eruptions are ten times longer and more luminous than those seen in typical QPEs. Each flare releases approximately one hundred times more energy than previous examples.
QPEs are often linked to black holes consuming stars. However, in Ansky’s case, there is currently no evidence of such an event, raising questions about the origin of the outbursts.
The flares were monitored using instruments from multiple agencies, including ESA’s XMM-Newton, NASA’s Chandra and NICER missions, as well as historical data from the eROSITA telescope.
Scientists believe these repeated X-ray bursts may also produce gravitational waves detectable by ESA’s upcoming LISA mission, scheduled for 2037. The combined analysis of X-ray and gravitational wave data may help clarify the behaviour of supermassive black holes.