At the center of almost every galaxy lies a supermassive black hole. Some of these black holes don't do much, while others experience a feeding frenzy and release huge amounts of energy into the universe as well as magnificent jets of particles.
Now, a team of researchers have studied the X-ray emissions of a supermassive black hole in exquisite detail. Their work, published in the Monthly Notices of The Royal Astronomical Society, focused on the Galaxy NGC 2992 and, in particular, emissions from the accretion disk of material surrounding its supermassive black hole.
Researchers caught the galaxy at its brightest flux levels in May 2019. These incredible flarings were an opportunity the researchers couldn’t miss. By using several X-ray observatories, they tracked flashes of X-rays that lasted for 90 minutes each at about 1.5 billion kilometers (930 million miles) from the supermassive black hole. This might seem a long distance but given that the galaxy is 110 million light-years away, it’s but a hair-width from the black hole.
“The ESA satellite XMM-Newton, together with NuSTAR and Swift (NASA), has caught the galaxy NGC 2992 in an extremely bright state, allowing us to measure the effects of the strong gravitational field around its supermassive black hole. We monitored its accretion disk for four days and observed intense variations on timescales of hours,” lead author Dr Andrea Marinucci, from the Italian Space Agency, told IFLScience.
“From the variability of the X-ray light curves, we estimated the mass of the supermassive black hole in NGC 2992 to be 30 million solar masses. We saw flares in its accretion disk at distances from the central black hole comparable to the ones between the Sun and Saturn, changing every 3-4 hours.”
The precise source of the flares is not clear. It's unlikely that a single region in the disk around the black hole is causing them. The researchers hope that future X-ray observatories such as Athena will provide more observations and help explain how these cosmic giants flare-up.
