Magnetic fields in NGC 1068 or M77 are displayed as streamlines over a composite image of visible light and X-rays of the galaxy from the Hubble Space Telescope, NuSTAR or the Nuclear Spectroscopic Array and Sloan Digital Sky Survey.
The magnetic fields align along the entire length of the massive spiral arms – 24,000 light years in diameter (0.8 kiloparsecs) – meaning that the gravitational forces that created the shape of the galaxy also compress its magnetic field.
This supports the leading theory of how the spiral arms are forced into their iconic shape known as the "density wave theory". SOFIA, the Stratospheric Observatory for Infrared Astronomy, used far infrared light (89 microns) to examine the galaxy to reveal facets of its magnetic fields that previous observations with visible and radio telescopes could not detect.
More information: How to Shape a Spiral Galaxy
Photo credit: NASA / SOFIA; NASA / JPL-Caltech / Roma Tre Univ. Last updated: December 28, 2020 Editor: Yvette Smith