Unveiling the disc-corona-wind driven accretion scenarios of BH-ULXs with XMM-Newton Observations

We present the results of a comprehensive long-term spectro-temporal analysis of ten ultra-luminous X-ray (ULX) black hole candidates namely IC 342 X-1, NGC 1313 X-1, NGC 5408 X-1, NGC 6946 X-1, NGC 55 ULX1, NGC 5204 X-1, NGC 4190 ULX1, NGC 4395 ULX1, M82 X-1 and NGC 247 ULX1 using XMM-Newton monitoring over a decade. Temporal studies reveal the presence of Quasi-periodic Oscillations (QPOs) with frequency ~ 8-667 mHz in five sources. The combination of thermal Comptonization and standard disc component are found to be the best description of the energy spectra (0.3-10 keV). A detailed spectro-temporal correlation study indicates dominance of Comptonized flux (50-90%) in the spectra over disc contribution (~50%) in presence of QPOs, associating these features with thermal Comptonization. Further, all the sources are found to exhibit a negative correlation between the disc luminosity and temperature ($L_{disc}\propto T_{\rm col}^{-\alpha}$) except NGC 5204 X-1, which shows a positive correlation ($L_{\rm disc}\propto T_{\rm col}^{+\alpha}$), closely connected with distinct spectral states. In summary, overall spectro-temporal findings and correlation properties of the sources suggest disc-corona-wind driven super-Eddington accretion scenarios of different configurations for massive stellar-mass to intermediate-mass BH-ULXs observed at various inclinations.