Around the Sun there are Birkeland currents and at a larger scale Milky Way Fermi Bubbles seem to be active and polarized by some unknown system . my proposal: former Herbig Haro bowshocks ( black holes) at different scales.
Polarization in the galaxy seems ( as gamma rays inside Fermi bubbles) to be also observed as Birkeland Alflen currents around the solar system.
see also: "Electric Birkeland Current Production Between Two Herbig Haro Black Holes" https://vixra.org/pdf/2002.0094v1.pdf
see also: M84 jets.: https://www.space.com/6153-black-holes-burp-big-bubbles.html
A monopole experiment:
M84. space.com
Milky Way bubbles.
