Two Quasi-periodic Oscillations in ESO 113-G010

In the Narrow-line Seyfert Galaxy (NLS1) ESO 113-G010, two Quasi-Periodic Oscillation (QPO) signals are detected in the XMM-Newton data collected in 2005 November. XMM-Newton has an exposure more than 100 ks in the energy range 0.3--10keV. The data was analyzed using the Lomb-Scargle Periodogram (LSP) and the Weighted Wavelet Z-transform (WWZ) method. It was found that there were sim2.24hours and sim4.09hours QPO in the observations with the confidence of 7.3sigma and 4.8sigma, respectively. The two QPO signals have a relationship of approximately 1:2 (1:1.83). The absence of QPOs in other observations of the object suggests that it is a transient phenomenon. The relationship between the mass of the ESO 113-G010 central black hole (BH) M_BH and its frequency f_QPO satisfies the similar logarithmic linear relationship in highly accreting BH systems, from BH X-ray binaries to supermassive BHs. The energy spectrum analysis reveals that the source has a soft excess below 1keV.