Probing the end of reionization with the near zones ofz≳ 6 QSOs

QSO near zones are an important probe of the ionization state of the intergalactic medium (IGM) at z 6-7, at the end of reionization. We present here high-resolution cosmological 3D radiative transfer simulations of QSO environments for a wide range of host halo masses, 10 10-12.5 M . Our simulated near zones reproduce both the overall decrease of observed nearzone sizes at 6 7 QSOs will provide important constraints on the evolution of the neutral hydrogen fraction and thus on how late reionization ends.