Supermassive black hole fires high-energy beam straight at Earth

A NASA mission observed a supermassive black hole pointing a high-energy beam toward Earth from a distance of 400 million light-years.

Simulation of Markarian 421 emitting a high-energy beam. Photo: NASA/Pablo Garcia — Simulation of Markarian 421 emitting a high-energy beam. Photo: *NASA/Pablo Garcia*

Active supermassive black holes are surrounded by rotating disks of material called accretion disks, which feed them over time. Some of the material they can’t swallow is then transferred to the poles, where it is then 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 pointed directly at Earth in an event called a blazar, Live Science reported on July 30.

The blazar, named 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 observes 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 accelerate also has a magnetic field with a twisted structure.

Blazars stretch through space for millions of light-years, but the mechanisms that create them are not yet fully 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 the study's lead author.

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 energies, and acting according to Einstein’s special theory of relativity. The blazer jets are also enhanced by the fact that their trajectory toward Earth amplifies the wavelength of light, 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 0% in the first and second observations. The team found that the rotating magnetic field resembled a corkscrew. Electromagnetic radiation measurements in the optical, infrared, and radio forms did not affect the beam’s stability or structure. This means that the shockwaves propagated along Markarian 421’s twisted magnetic fields. 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 identify other blazars with similar characteristics to understand the mechanism behind the phenomenon.

An Khang (According to Live Science )

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