Active supermassive black holes are surrounded by a rotating disk of material called an accretion disk, which feeds them over time. Some of the material they can’t swallow is then funneled to the poles, where it’s ejected at nearly the speed of light. This process produces extremely bright, high-energy electromagnetic radiation. In some cases, like the one NASA recently detected, the beam is aimed directly at Earth in an event called a blazar, Live Science reported on July 30.

The blazar, called Markarian 421, is located in the constellation Ursa Major and was observed by NASA's Imaging X-ray Polarimetry Explorer (IXPE) mission, launched in December 2021. IXPE looks at a feature of magnetic fields called polarization, which indicates the direction of the magnetic field. The polarization of the jet ejected from Markarian 421 shows that the part of the jet where the particles are accelerating also has a magnetic field with a twisted structure.

Blazars stretch across space for millions of light years, but the mechanisms that create them are still poorly understood. However, the new findings surrounding Markarian 421 may help shed light on this cosmic phenomenon, said Laura Di Gesu, an astrophysicist at the Italian Space Agency and lead author of the study.

The main reason why an active supermassive black hole’s jets are so bright is because the particles approach the speed of light, emitting enormous amounts of energy, and acting according to Einstein’s special theory of relativity. The blazars are also enhanced by the fact that as they are directed toward Earth, the wavelength of the light is amplified, increasing both frequency and energy. The result is that blazars can be brighter than all the light from all the stars in the galaxy combined. Now, IXPE is using that light to map out the physics at the center of Markarian 421’s jet and identify the source of the glowing beam.

Analysis of the IXPE data showed that the beam’s polarization dropped to zero in the first and second observations. The team found that the magnetic field rotated like a corkscrew. Measurements of electromagnetic radiation in the form of optical, infrared, and radio light did not affect the beam’s stability or structure. This means that the shockwaves propagated along the twisted magnetic fields of Markarian 421. The new findings provide the clearest evidence yet that the twisted magnetic fields contribute to the shockwaves that accelerate particles in the beam.

The team plans to continue exploring Markarian 421 as well as identifying other blazars with similar characteristics to understand the mechanism behind the phenomenon.

An Khang (According to Live Science )