ArH+ and H2O+ absorption towards luminous galaxies Arshia M. Jacob, Karl M. Menten, Friedrich Wyrowski, Benjamin Winkel, David A. Neufeld and Bärbel S. Koribalski A&A, 659 (2022) A152 Published online: 21 March 2022 DOI: 10.1051/0004-6361/202142544