We report the discovery of a quasi-periodic oscillation ( QPO ) at 642 mHz in an XMM-Newton observation of the ultraluminous X-ray source ( ULX ) IC 342 X-1 .
The QPO has a centroid at \nu _ { QPO } = 642 \pm 20 mHz , a coherence factor of Q = 11.6 , and an amplitude ( rms ) of 4.1 % with significance of 3.6 \sigma .
The energy dependence study shows that the QPO is stronger in the energy range 0.3 - 5.0 keV .
A subsequent observation ( 6 days later ) does not show any signature of the QPO in the power density spectrum .
The broadband energy spectra ( 0.3 - 40.0 keV ) obtained by quasi-simultaneous observations of XMM-Newton and NuSTAR can be well described by an absorbed diskbb plus cutoffpl model .
The best fitted spectral parameters are power-law index ( \Gamma ) \sim 1.1 , cutoff energy ( E _ { c } ) \sim 7.9 keV and disc temperature ( kT _ { in } ) \sim 0.33 keV , where the QPO is detected .
The unabsorbed bolometric luminosity is \sim 5.34 \times 10 ^ { 39 } erg s ^ { -1 } .
Comparing with the well known X-ray binary GRS 1915+105 , our results are consistent with the mass of the compact object in IC 342 X-1 being in the range \sim 20 - 65 ~ { } M _ { \odot } .
We discuss the possible implications of our results .