X-ray emission of z > 2.5 active galactic nuclei can be obscured by their host galaxies C. Circosta, C. Vignali, R. Gilli, A. Feltre, F. Vito, F. Calura, V. Mainieri, M. Massardi and C. Norman A&A, 623 (2019) A172 Published online: 28 March 2019 DOI: 10.1051/0004-6361/201834426