Unveiling the impact of black hole spin on flickering of light emitted from matter around the black hole

Scientists from the Aryabhatta Research Institute of Observational Sciences (ARIES), alongside international and domestic academic partners, have uncovered how black hole spin impacts the flickering of light, or quasi-periodic oscillations (QPOs), in X-rays emitted from matter around black holes. Utilizing computer simulations that account for relativistic fluid dynamics and internal viscosity, the study demonstrated that rapidly spinning black holes pull accretion shocks closer, producing a wide range of high-frequency oscillations up to over 100 Hz. Conversely, slowly spinning black holes push shocks outward, resulting in low-frequency QPOs.