From millions of light-years away, how can we tell if a galaxy contains one supermassive black hole or two? It’s a tricky problem: the gas around single supermassive black holes glows across the electromagnetic spectrum and varies on timescales from hours to years, and it’s not obvious how adding a second black hole changes these behaviors. As a step toward differentiating the two scenarios, a team led by John Ryan Westernacher-Schneider (Leiden University and Clemson University) simulated the gas surrounding pairs of black holes. When binary black hole systems ensnare gas from their surroundings, the gas collects in a large accretion disk around both black holes and in smaller disks around the individual black holes. These smaller disks are called minidisks. Each frame above shows a simulated minidisk with different physical parameters. Because of instabilities, the simulated minidisks sometimes become extremely elongated, and if future work suggests that this elongation is likely to happen in real disks, it may provide a way to interpret variations in the light from distant sources and pinpoint binary black holes. To learn more about these minidisk simulations, be sure to check out the full article linked below.
Citation
“Eccentric Minidisks in Accreting Binaries,” John Ryan Westernacher-Schneider et al 2024 ApJ 962 76. doi:10.3847/1538-4357/ad1a17