Astronomers spot the ‘Eye of Sauron’ in deep house|ERC

An worldwide staff of researchers made a discovery that can assist in understanding how a seemingly slow-moving blazar, often called PKS 1424+240, could possibly be one of many brightest sources of high-energy gamma rays and cosmic neutrinos ever noticed. Their outcomes are printed in the present day within the journal Astronomy & Astrophysics Letters.

Located billions of light-years away, the blazar PKS 1424+240 had lengthy baffled astronomers. It stood out because the brightest identified neutrino-emitting blazar within the sky — as recognized by the IceCube Neutrino Observatory — and was additionally glowing in very high-energy gamma rays noticed by ground-based Cherenkov telescopes. Yet, oddly, its radio jet appeared to maneuver sluggishly, contradicting expectations that solely the quickest jets can energy such intense high-energy emissions.

Now, thanks to fifteen years of ultra-precise radio observations from the Very Long Baseline Array (VLBA), researchers have stitched collectively a deep picture of this jet at unparalleled decision.

‘When we reconstructed the image, it looked absolutely stunning,’ says Yuri Kovalev, lead writer of the research and Principal Investigator of the ERC-funded MuSES mission on the Max Planck Institute for Radio Astronomy (MPIfR). ‘We have never seen anything quite like it — a near-perfect toroidal magnetic field with a jet, pointing straight at us.’

Because the jet is aligned virtually precisely within the course of Earth, its high-energy emission is dramatically amplified by the results of particular relativity. ‘This alignment causes a boost in brightness by a factor of 30 or more,’ explains Jack Livingston, a co-author at MPIfR. ‘At the same time, the jet appears to move slowly due to projection effects — a classic optical illusion.’

This head-on geometry allowed scientists to see immediately into the center of the blazar’s jet — a particularly uncommon alternative. Polarized radio alerts helped the staff map out the construction of the jet’s magnetic discipline, revealing its probably helical or toroidal form. This construction performs a key position in launching and collimating the plasma circulation, and could also be important for accelerating particles to excessive energies.

‘Solving this puzzle confirms that active galactic nuclei with supermassive black holes are not only powerful accelerators of electrons, but also of protons — the origin of the observed high-energy neutrinos,’ concludes Kovalev. 

The discovery is a triumph for the MOJAVE program, a decades-long effort to observe relativistic jets in energetic galaxies utilizing the VLBA. Scientists make use of the strategy of Very Long Baseline Interferometry (VLBI), which connects radio telescopes throughout the globe to type a digital telescope the dimensions of the Earth. This gives the very best decision out there in astronomy, permitting them to check the advantageous particulars of distant cosmic jets.

‘I am thrilled that MOJAVE continues to produce groundbreaking results,’ says Anton Zensus, Director at MPIfR and co-founder of this system. ‘We began this project in 1994 — long before the first cosmic neutrino was even detected. And now we’re uncovering the mechanisms behind these unimaginable phenomena.’

This outcome strengthens the hyperlink between relativistic jets, high-energy neutrinos, and the position of magnetic fields in shaping cosmic accelerators — marking a milestone in multimessenger astronomy.

 

Additional Information

A blazar is a sort of energetic galactic nucleus powered by a supermassive black gap that launches a jet of plasma shifting at almost the pace of sunshine. What makes a blazar particular is its orientation: one among its jets is pointed inside about 10 levels of Earth. This alignment makes blazars seem brilliant throughout the electromagnetic spectrum and permits scientists to check excessive bodily processes — together with the acceleration of particles to energies far past these achieved in human-made accelerators.

The VLBA (Very Long Baseline Array) is an array of ten antennas, at areas throughout the continental United States and in Hawaii and St Croix, which operates within the very lengthy baseline interferometry (VLBI) mode. Spacings between the antennas range as much as roughly ten thousand kilometers, offering angular decision on the sky as advantageous as 50 micro-arcseconds.

MOJAVE (Monitoring Of Jets in Active galactic nuclei with VLBA Experiments) is a long-term program to observe radio brightness and polarization variations in jets related to energetic galaxies seen within the northern sky.  The observations are made with the Very Long Baseline Array, which allows us to make full polarization photos with an angular decision higher than 1 milliarcsecond (the obvious separation of your automotive’s headlights, as seen by an astronaut on the Moon). We are utilizing these knowledge to higher perceive the complicated evolution and magnetic discipline buildings of jets on light-year scales, near the place they originate within the energetic nucleus, and the way this exercise is correlated with a excessive vitality electromagnetic and neutrino emission.

MuSES, which stands for Multi-messenger Studies of Energetic Sources, is a pioneering initiative in astrophysics. It is devoted to the research of Active Galactic Nuclei, that are among the many strongest particle accelerators identified within the cosmos. These celestial our bodies harness the gravitational vitality of matter accreted by supermassive black holes and convert it into electromagnetic and kinetic vitality, ensuing within the manufacturing of extremely relativistic electrons and protons. The acceleration of protons and its relation to neutrino manufacturing will not be properly understood, posing a formidable problem to researchers. MuSES goals to deal with these elementary questions by exploiting latest advances in multi-messenger astronomy.

The MuSES mission has acquired funding from the European Union (ERC grant settlement No 101142396). Views and opinions expressed are nevertheless these of the writer(s) solely and don’t essentially mirror these of the European Union or ERCEA. Neither the European Union nor the granting authority might be held accountable for them.

 

Original Paper:

Y. Y. Kovalev, A. B. Pushkarev, J. L. Gomez, D. C. Homan, M. L. Lister, J. D. Livingston, I. N. Pashchenko, A. V. Plavin, T. Savolainen, S. V. Troitsky: Looking into the Jet Cone of the Neutrino-Associated Very High Energy Blazar PKS 1424+240, A&A Letters, August 12, 2025 (DOI: 10.1051/0004-6361/202555400)

https://doi.org/10.1051/0004-6361/202555400

Preprint: https://arxiv.org/abs/2504.09287

 

Further Information/Links:

Multi-messenger Studies of Extragalactic Super-colliders (MuSES), ERC Grant

Monitoring Of Jets in Active galactic nuclei with VLBA Experiments (MOJAVE) program

Max Planck Institute for Radio Astronomy (MPIfR)

Very Long Baseline Array (VLBA)