Faint, unobscured quasars at z>6

The SMBHs selected in this study, on average, exhibit an elevated mass compared to their hosts, with the mass ratio distribution slightly higher than those of galaxies in the local Universe. As with other high-z studies, this is at least in part due to the selection method for these quasars. An extensive Monte Carlo analysis provides compelling evidence that heavy black hole seeds from the direct collapse scenario appear to be the preferred pathway to mature this specific subset of SMBHs by z~7.

Notably, most of the selected candidates might have emerged from seeds with masses of ~10^5^M_{sun}_, assuming a thin disk accretion with an average Eddington ratio of f_Edd_=0.6+/-0.3 and a radiative efficiency of epsilon=0.2+/-0.1. This work underscores the significance of further spectroscopic observations, as the quasar candidates presented here offer exceptional opportunities to delve into the nature of the earliest galaxies and SMBHs that formed during cosmic infancy.