Planck intermediate results. XLII. Large-scale Galactic magnetic fields

R Adam, Planck Collaboration, P.A.R Ade, M.I.R. Alves, M. Ashdown, J. Aumont, C. Baccigalupi, A.J. Banday, R.B. Barreiro, Elena Bartoloni, E. Battaner, Per Rex Christensen, Pavel Nasselski, Hans Ulrik Nørgaard-Nielsen