Abstract There are now four low mass X-ray binaries with black holes which show twin resonant-like HFQPOs. Similar QPOs might have been found in Sgr A*. I review the power spectral density distributions of the three X-ray flares and the six NIR flares published for Sgr A* so far, in order to look for more similarities than just the frequencies between the microquasar black holes and Sgr A*. The three X-ray flares of Sgr A* are re-analysed in the same way and white noise probabilities from their power density distributions are given for the periods reported around ˜ 1100 s. Progress of the resonant theory using the anomalous orbital velocity effect is summarized.

Keywords Galaxy: center X-rays: general black hole physics X-rays: individuals Sgr A*

null