Program: GS-2021A-Q-418

Black hole mass is one of the key parameters in understanding black hole physis as well as the seed and growth of AGNs. Reverberation-mapping provides virial mass measurements and the fundamental calibation of indirect mass estimatiors based on the emprical broad-line region size - AGN luminosity relation. However, the current reverberation-mapped AGNs with reliable H beta lag measurements are limited to moderate luminosity AGNs, without covering the typical luminous QSOs observed at relatively high-z. We plan GMOS spectroscopy monitoring for a sample of uniquely selected high-luminosity QSOs with expected H beta lag of 300-400 light days, which are most suitable targets to a multi-year monitoring project because of the minimized effect of the seasonal gap in the light curves. We will be able to properly the validity of the size-luminosity relation at high luminosity end. With this poor weather program, we will obtain an initial spectrum of each target, which will be used for emission line decompostion to setup the best observation strategy for the long-term campaign.