Bayesian timing analysis of giant flare of SGR 1806-20 by RXTE PCA

Aims. By detecting high-frequency quasi-periodic oscillations (QPOs) and estimating their frequencies during the decaying tail of giant flares from soft gamma-ray repeaters (SGRs) useful constraints for the equation of state (EoS) of superdense matter may be obtained via comparison with theoretical predictions of eigenfrequencies. Methods. We used the data collected by the Rossi X-Ray Timing Explorer (RXTE/XTE) Proportional Counter Array (PCA) of a giant flare of SGR 1806-20 on 2004 Dec. 27 and applied an existing Bayesian periodicity detection method to search for oscillations of a transient nature. Results. In addition to the already detected frequencies, we found a few new frequencies (f(QPOs) similar to 16.9, 21.4, 36.4, 59.0, 116.3 Hz) of predicted oscillations based on the APR(14) EoS for SGR 1806-20.