We report the results of the analysis of an AstroSat observation of the Black Hole candidate MAXI J1535-571 during its Hard Intermediate state. We studied the evolution of the spectral and timing parameters of the source during the observation. The observation covered a period of ∼5 days and consisted of 66 continuous segments, corresponding to individual spacecraft orbits. Each segment was analysed independently. The source count rate increased roughly linearly by ∼30 %. We modelled the spectra as a combination of radiation from a thermal disk component and a power-law. The timing analysis revealed the presence of strong Quasi Periodic Oscillations with centroid frequency νQPO fluctuating in the range 1.7-3.0 Hz. We found a tight correlation between the QPO centroid frequency νQPO and the power-law spectral index Γ, while νQPO appeared not to be correlated with the linearly-increasing flux itself. We discuss the implications of these results on physical models of accretion.
@article{arxiv.1906.10595,
title = {Spectro-timing analysis of MAXI J1535-571 using AstroSat},
author = {Yash Bhargava and Tomaso Belloni and Dipankar Bhattacharya and Ranjeev Misra},
journal= {arXiv preprint arXiv:1906.10595},
year = {2019}
}