2013MNRAS.433..412L

We investigate the properties of the centroid frequency of low-frequency quasi-periodic oscillation (LF QPOs, 0.1-30 Hz) during the 2003 outburst of H1743-322, by using the observational data of the Rossi X-ray Timing Explorer. We find that the frequency shows different energy dependences for each of the sub-classes of LF QPOs: the QPO frequency is proportional to photon energy for the type C QPOs while it is ambiguous for the type A and B QPOs. For type C QPOs, the slope of the frequency-energy relation versus frequency plot can be well described by a power law with frequency till ∼ 7.5 Hz. Beyond ∼ 7.5 Hz the slope goes down. The LF QPO amplitude decreases monotonically with the frequency for the type C but increases for the other two types. These properties provide a joint diagnostic for discriminating the different types of LF QPO.