Scientists from the Israel Institute of Technology (Technion) have reported evidence that flares resembling solar storms may occur near supermassive black holes. Such black holes can be a million times larger than the Sun or more. The phenomenon was detected in the vicinity of a black hole in the galaxy NGC 3783, and the results were published in The Astrophysical Journal Letters.
Solar storms are powerful emissions of X-ray radiation together with streams of charged particles that travel from the solar corona (the outer layer of the Sun's atmosphere) into space. They are dangerous for astronauts and can interfere with satellite communications. Such emissions, called coronal mass ejections, arise when magnetic energy is converted into kinetic energy - the energy of motion - in a process of magnetic reconnection.
In the new work, researchers for the first time recorded signs of magnetic reconnection and a coronal mass ejection at a black hole. Observations were made of X-ray radiation near the black hole using the XRISM space telescope. The detected phenomenon is known as the "Neuper effect": it was first described on the Sun in 1968, but had not previously been observed at black holes. This indicates that the same physical processes that underlie solar storms may also operate in the vicinity of supermassive black holes.
The study was led by Gal Vardi, a doctoral student in the Technion physics faculty, under the supervision of Professor Ehud Behar. Scientists from Japan, Europe and the United States took part in the work. In addition to XRISM - a joint mission of NASA, the Japan Aerospace Exploration Agency (JAXA) and the European Space Agency (ESA) - ESA's XMM-Newton space telescope was used.
The authors emphasize that these are evidence in favor of a similarity of processes, not direct proof that solar storms and flares at black holes are caused by the same mechanism. In addition, the observations relate to a single galaxy, so the conclusions cannot yet be automatically extended to all supermassive black holes.