Empirical relations between the intensities of Lyman lines of H and He+ M. Gordino, F. Auchère, J.-C. Vial, K. Bocchialini, D. M. Hassler, T. Bando, R. Ishikawa, R. Kano, K. Kobayashi, N. Narukage et al. (2 more) A&A, 657 (2022) A86 Published online: 18 January 2022 DOI: 10.1051/0004-6361/202141960