The magnetic fields in the halo of NGC 4631 show magnetic fields that reverse direction in a regular fashion. A magnetic dynamo could explain this behaviour, never before seen in a galaxy’s halo. See https://public.nrao.edu/news/giant-magnetic-ropes/ for more information.
A study of spiral galaxies seen edge-on has revealed that “halos” of cosmic rays and magnetic fields above and below the galaxies’ disks are much more common than previously thought. See the spectacular image and read the full story at:
First published in November 14, 2013, Astronomers studying gas halos around nearby galaxies were surprised when detailed studies with the National Science Foundation’s Karl G. Jansky Very Large Array (VLA) showed that one of their subjects is not a single galaxy, but rather two, nearly perfectly superimposed on the sky to masquerade as one. The discovery allowed them to use the alignment to learn otherwise-unobtainable facts about the nearer galaxy. Please read more at