The comptonizing medium of the black hole X-ray binary MAXI J1535?571 through type-C quasi-periodic oscillations

We present a detailed spectral and temporal analysis of the black-hole candidate MAXI~J1535$-$571 using NICER observations in September October 2017. focus specifically on hard-intermediate state when source shows type-C quasi-periodic oscillations (QPOs). fitted time-averaged spectrum rms phase-lag spectra QPO with one-component time-dependent Comptonization model. found that corona contracts from $\sim 10^4$ to 3 \times 10^3$ km as frequency increases 1.8$ Hz 9.0$ Hz. The fits suggest system would consists two coronas, small one dominates larger one, possibly jet, lag QPO. significant break relation parameters properties QPO, including its spectra, frequency. change relations happens crosses critical $\nu_c \approx 3.0$ Interestingly, reaches this simultaneously radio emission jet is quenched.