The discovery of 3:2 quasi-periodic oscillations ( QPOs ) in the ultraluminous X-ray source NGC 1313 X-1 suggests it harbors an intermediate-mass black hole ( IMBH ) .
We test this numerically by modelling the 3:2 QPOs and the associated X-ray spectrum based on the epicyclic resonance model and a disk-corona model with large-scale magnetic fields generated by the Cosmic Battery mechanism .
The combined QPO-frequency and spectral fitting indicates that the BH mass ranges from 2524 M _ { \odot } to 6811 M _ { \odot } confirming its IMBH nature , and the BH spin is probably higher than \sim 0.3 .