Averaged radial and vertical profile of B of galaxies at various redshifts, and their 1σ width (top). In the top left panel, we show the total magnetic strength profile of NGC6946 (Beck 2007) and M101 (Berkhuijsen et al. 2016). In the top right panel, we show the average vertical B profiles of CHANG-ES galaxies (Krause et al. 2018) with a scale-height of 6 ± 3 kpc. Averaged radial and vertical n_e profile of galaxies at various redshifts, and their 1σ width (bottom). We overplotted the n_e profiles of the thick disk from Yao et al. (2017).