"Discovery of Quasi-Periodic X-ray Oscillations in GX 339-4"

Chinese astronomers using the Hard X-ray Modulation Telescope (HXMT) have observed the latest outburst of the black hole X-ray binary system GX 339-4 and detected new quasi-periodic oscillations (QPOs). The QPOs were classified as Type-C and were found to occur during the transition from the low-hard state to the hard-intermediate state. The observations also revealed a phase lag behavior and a correlation between the root-mean-square (rms) of the QPOs and photon energy. Further research is needed to understand the physical mechanisms behind these findings.