Copyright © 2020, Oxford University PressRodríguez Espinosa, J. M.Mas Hesse, J. M.Salvador Solé, E.Calvi, R.Manrique, AlbertoChanchaiworawit, K.Guzman, R.Gallego, J.Herrero, A.Marín Franch, A.Unidad de Excelencia Científica María de Maeztu Centro de Astrobiología del Instituto Nacional de Técnica Aeroespacial y CSIC, MDM-2017-07372021-04-082021-04-082020-03-18Monthly Notices of the Royal Astronomical Society: Letters 495(1): L17- L21 (2020)1745-3925https://academic.oup.com/mnrasl/article/495/1/L17/5809363http://hdl.handle.net/20.500.12666/157We show herein that a proto-cluster of Ly α emitting galaxies, spectroscopically confirmed at redshift 6.5, produces a remarkable number of ionizing continuum photons. We start from the Ly α fluxes measured in the spectra of the sources detected spectroscopically. From these fluxes, we derive the ionizing emissivity of continuum photons of the protocluster, which we compare with the ionizing emissivity required to reionize the protocluster volume. We find that the sources in the protocluster are capable of ionizing a large bubble, indeed larger than the volume occupied by the protocluster. For various calculations, we have used the model AMIGA, in particular to derive the emissivity of the Lyman continuum photons required to maintain the observed volume ionized. Besides, we have assumed the ionizing photons escape fraction given by AMIGA at this redshift.engGalaxies: high redshiftGalaxies; star formationCosmology: reionizationCosmology: early universeinfo:eu-repo/semantics/article10.1093/mnrasl/slaa0451745-3933info:eu-repo/semantics/restrictedAccess