No High Frequency Quasi-Periodic Oscillations from the X-ray burster 1E1724-3045 Original Research Article

The type I X-ray burster 1E1724-3045 located in the globular cluster Terzan 2 was observed by the Rossi X-ray Timing Explorer (RXTE) while it was in a Island state, displaying both intense flickering and a hard Comptonized spectrum. No statistically significant High Frequency Quasi-Periodic Oscillations (HFQPOs) were detected. A 3σ upper limit on the fractional Root Mean Squared (RMS) of ∼ 2.5% has thus been derived in the 5–30 keV band. Attenuation of the QPO signal in a scattering corona of optical depth ∼ 3 as inferred from the spectral analysis could provide an explanation for the non-detection of HFQPOs from 1E1724-3045.