A small and vigorous black hole in the early Universe by Maiolino, R, Scholtz, J, Witstok, J, Carniani, S, D’Eugenio, F, de Graaff, A, Übler, H, Tacchella, S, Curtis-Lake, E, Arribas, S, Bunker, A, Charlot, S, Chevallard, J, Curti, M, Looser, TJ, Maseda, MV, Rawle, TD, Rodríguez del Pino, B, Willott, CJ, Egami, E, Eisenstein, DJ, Hainline, KN, Robertson, B, Williams, CC, Jones, GC