What excites the optical emission in X-ray-selected galaxies? N. G. Pulatova, H.-W. Rix, A. V. Tugay, L. V. Zadorozhna, R. Seeburger and M. Demianenko A&A, 686 (2024) A223 Published online: 14 June 2024 DOI: 10.1051/0004-6361/202347983