Convection-driven spherical shell dynamos at varying Prandtl numbers P. J. Käpylä, M. J. Käpylä, N. Olspert, J. Warnecke and A. Brandenburg A&A, 599 (2017) A4 Published online: 20 February 2017 DOI: 10.1051/0004-6361/201628973