Black hole at the core of a galaxy periodically brightens up

X-ray Quasi-Periodic Eruptions (QPEs) from the black hole at the core of GSN 069 as observed with XMM-Newton and Chandra. In each panel, the X-ray amplitude is relative to the ‘quiescent’ level. [credit: G. Miniutti, CAB]

During an ESA’s XMM-Newton observation on 2018 Christmas Eve, an international team led by Giovanni Miniutti, of the Centro de Astrobiolog√≠a (CAB, CSIC-INTA) in Madrid, discovered some mysterious flashes from the active black hole at the core of the galaxy GSN 069, about 250 million light years away. X-ray emission from the center of that galaxy was seen to suddenly increase its brightness by up to a factor 100, then dimmed back to its normal levels within one hour and lit up again nine hours later. Giant black holes regularly flicker like a candle but the rapid, repeating changes seen in GSN 069 had never been observed before from supermassive black hole at the core of galaxies.

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The response of relativistic outflowing gas to the inner accretion disk of a black hole

Artist impression illustrating a super-massive black hole with X-ray emission emanating from its inner region (pink) and ultrafast winds streaming from the surrounding disk (purple). Credit: ESA

Active Galactic Nuclei (AGN) are thought to have a profound effect on large scales through feedback mechanisms. AGN gas outflows release vast amounts of energy into the interstellar medium and can clear out the surrounding gas, possibly regulating star formation in the host galaxy as well as preventing further gas accretion onto the black hole. Such feedback may well contribute to the intimate observed relationship between the central black hole and the host galaxy properties.

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