An ionised bubble before the epoch of re-ionisation

Re-ionisation brought a major change in the history of the Universe. Most theories assume that re-ionisation proceeded in patches and lasted for some time. Observations, on the other hand have claimed that it was the low luminosity star forming sources that were responsible for ionising the Universe. In a search for Lyman Alpha sources around two spectroscopically confirmed star forming sources in the Subaru Deep Field, we have found some 45 low luminosity star forming galaxies.  We find that these sources form a proto-cluster. Moreover,  they reside in an ionised bubble of at least 12000 cMpc^3. To the best of our understanding, it is the first time that an ionised bubble has ben seen and characterised before the epoch of re-ionsation of the Universe. I will show that not only the volume containing the proto-cluster is ionised, but that there is still sufficient ionising photons escaping the bubble to contribute to the re-ionisation of the Universe.