Israeli Astrophysicists Discover Solar Storm Analog Near Supermassive Black Hole

Astrophysicists from Israel's Technion, in collaboration with international colleagues, have for the first time detected a flare near the supermassive black hole at the center of galaxy NGC 3783, originating from the same mechanism that causes solar storms. On the Sun, flares and coronal mass ejections are generated by magnetic reconnection, where magnetic field lines reconfigure, converting stored magnetic energy into plasma heating, particle acceleration, and kinetic energy for the ejection. Active galactic nuclei, like those around black holes, also possess hot coronae that emit X-rays. While scientists long suspected similar processes occurred at black holes as on our Sun, direct evidence was lacking until this international team, led by Technion researchers, obtained it. Their findings were published in the Astrophysical Journal Letters. The researchers analyzed ten days of observations of NGC 3783 from July 2024, using data from the XRISM and XMM-Newton satellite X-ray observatories. The black hole in NGC 3783 has a mass approximately 28 million times that of the Sun. During one observed X-ray flare, the rate of increase in soft radiation was found to be proportional to the flux of hard radiation, an effect first identified on the Sun in 1968. This phenomenon occurs because accelerated particles from reconnection produce hard radiation, while the plasma they heat accumulates and emits in the soft spectrum. This specific effect had not been observed near black holes before. Simultaneously with the flare, an ultra-fast wind emerged, traveling at about 0.19 times the speed of light, which the researchers identify as the analog of a solar coronal mass ejection. The study authors stated, "Although the existence of magnetic reconnection in the coronae of active galactic nuclei has long been hypothesized, this paper presents the first direct detection of it." The scale of this black hole's coronal mass ejection is immense. The magnetic loop believed to have generated the flare extended 1.2 billion kilometers above the black hole, a distance comparable to that between the Sun and Saturn. In contrast, similar loops on the Sun typically extend tens of thousands of kilometers, making the black hole's loop tens of thousands of times larger.