The 500 ks Chandra observation of the z = 6.31 QSO SDSS J1030 + 0524 R. Nanni, R. Gilli, C. Vignali, M. Mignoli, A. Comastri, E. Vanzella, G. Zamorani, F. Calura, G. Lanzuisi, M. Brusa et al. (16 more) A&A, 614 (2018) A121 Published online: 03 July 2018 DOI: 10.1051/0004-6361/201832694