IXPE Illustration Markarian 421

This NASA illustration shows the structure of a black hole jet as inferred by recent observations of the blazar Markarian 421 by the Imaging X-ray Polarimetry Explorer (IXPE). The jet is powered by an accretion disk, shown at the bottom of the image, which orbits and falls into the black hole over time. Helical magnetic fields are threaded through the jet. IXPE observations have shown that the X-rays must be generated in a shock originating within material spiraling around the helical magnetic fields. The inset shows the shock front itself. X-rays are generated in the white region nearest the shock front, whereas optical and radio emission must originate from more turbulent regions further away from the shock.