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In the narrow-line Seyfert 1 galaxy 1H 0707-495, recently a transientquasi-periodic oscillation (QPO) signal with a frequency of $\sim 2.6\times10^{-4}$ Hz has been detected at a high statistical significance. Here, wereanalyze the same set of XMM-Newton data observed on 2008 February 4 with theWeighted-Wavelet Z-transform (WWZ) method. In addition to confirming theprevious findings, we also find another QPO signal with a frequency of $\sim1.2\times 10^{-4}$ Hz in a separated X-ray emission phase at the significancelevel of $\sim 3.7\sigma$. The signal is also found fitting an auto-regressivemodel though at a lower significance. The frequency ratio between these twosignals is $\sim 2:1$. The analysis of other XMM-Newton measurements of 1H0707-495 also reveals the presence of the $\sim 2.6\times 10^{-4}$ Hz ($\sim1.2\times 10^{-4}$ Hz) QPO signal on 2007 May 14 (2010 September 17) at thesignificance level of $\sim 4.2\sigma$ ($\sim 3.5\sigma$). The QPO frequencyfound in this work follows the $f_{QPO}-M_{BH}$ relation reported in previousworks spanning from stellar-mass to supermassive black holes. This is the firsttime to observe two separated transient X-ray QPO signals in active galacticnuclei (AGNs), which sheds new light on the physics of accreting supermassiveblack holes.

Two transient X-ray Quasi-Periodic Oscillations separated by an intermediate state in 1H 0707-495