Eye of Sauron image maps a powerful blazar jet

A high resolution radio image of a distant blazar reveals a toroidal magnetic field guiding a relativistic jet and helps explain bright gamma rays and neutrinos.

Eye of Sauron image maps a powerful blazar jet

New radio images from the MOJAVE program show PKS 1424+240, a blazar powered by a supermassive black hole, with a jet that appears nearly straight toward Earth. The jet’s geometry and a toroidal magnetic field explain why this distant source has produced bright high energy gamma rays and neutrinos.

The findings, published in Astronomy & Astrophysics 2025, rely on 15 years of Very Long Baseline Array observations. They reveal a near perfect toroidal magnetic field guiding a jet that is strongly beamed, a combination that makes the emission visible across the electromagnetic spectrum and beyond. The work strengthens the link between relativistic jets and particle acceleration, showing how magnetic fields shape the engines at the heart of active galaxies.

This result addresses a long standing question about how a jet that looks slow can still power extreme emissions. By showing the magnetic field geometry, the study offers a concrete mechanism for accelerating particles to the highest energies. It also demonstrates how high resolution radio imaging can connect electromagnetic signals with neutrinos. Still, scientists will test the idea across more jets to see if the toroidal field pattern is common or a quirk of PKS 1424+240.

Highlights

The cosmos still hides its engines and better instruments will reveal more