BH growth rates. Birth redshifts are z = 10 and 20, and we consider mass losses of 10% and 50%. The AGN and its error bars in mass are marked by the solid black circle. Green is the 9000 M_⊙ BH growing at 0.5 L_Edd, blue is the 500 M_⊙ BH growing at L_Edd, cyan is the 500 M_⊙ BH growing at 0.5 L_Edd, magenta is the 2700 M_⊙ BH growing at L_Edd, and red is the 1500 M_⊙ BH growing at L_Edd. Observational constraints on the accretion rate of the AGN at z = 5.55 are 0.1–1.6 L_Edd (X. Ji et al. 2024).