The GREATS Hβ+[O III]Luminosity Function and Galaxy Properties at $\mathbf {z\sim 8}$: Walking the Way of JWST

[1 ]Département d'Astronomie, Université de Gen‘eve, 51 Ch. des Maillettes, 1290 Versoix, Switzerland

[2 ]International Associate, Cosmic Dawn Center (DAWN) at the Niels Bohr Institute, University of Copenhagen and DTU-Space, Technical University of Denmark

[3 ]Centre for Astrophysics & Supercomputing, Swinburne University of Technology, PO Box 218, Hawthorn, VIC 3112, Australia

[4 ]Leiden Observatory, Leiden University, NL-2300 RA Leiden, Netherlands

[5 ]Departmento de Astronomia, Universidad de Chile, Casilla 36-D, Santiago 7591245, Chile

[6 ]Centro de Astrofisica y Tecnologias Afines (CATA), Camino del Observatorio 1515, Las Condes, Santiago 7591245, Chile

[7 ]Cavendish Laboratory, University of Cambridge, 19 JJ Thomson Avenue, Cambridge CB3 0HE, UK

[8 ]Kavli Institute for Cosmology, University of Cambridge, Madingley Road, Cambridge CB3 0HA, UK

[9 ]UCO/Lick Observatory, University of California, Santa Cruz, CA 95064, USA