Estimating the spins of supermassive black holes in distant ultraluminous quasars

In this paper, we estimated spin, inclination angle and corresponding supermassive black hole(SMBH) mass values for sample of extremely distant ([Formula: see text]) ultraluminous quasars. The estimated spin values are on average greater than 0.9 and the spin distribution has a characteristic appearance, similar to ones obtained for other types of AGNs and quasars. The dependence of estimated parameters on each other shows strong correlations between them, from which we can assume that in this early quasars, the growth of SMBHs mass should occur mainly due to disk accretion with high accretion rate, which very effectively increases the spin.