All massive galaxies are thought to host supermassive black holes (SMBH). When the black holes are actively accreting materials and emitting radiation, astrophysicists name them lively galactic nuclei (AGN). Some AGN emit relativistic jets, streams of ionized matter shifting at close to the velocity of sunshine. When these highly effective jets are pointed at us, we name them blazars.
Blazars are excessive and enigmatic objects, and astrophysicists have unanswered questions on them. The mechanisms behind their jets are poorly understood. What position do magnetic fields play? How are particles within the jets accelerated in order that they emit gamma rays? How do they emit neutrinos? Some jets lengthen for 1000’s of sunshine years, but are variable in timescales as brief as a couple of minutes. What causes that?
Blazars are AGN that emit highly effective jets of energetic, high-velocity particles aimed in our path. They’re typically known as Nature’s particle accelerators. Picture Credit score: Marscher et al., Wolfgang Steffen, Cosmovision, NRAO/AUI/NSF
New analysis in Astronomy and Astrophysics is offering a solution to one of many cussed questions. It is titled “Looking into the jet cone of the neutrino-associated very high-energy blazar PKS 1424+240.” The lead creator is Yuri Kovalev, Principal Investigator of the MuSES undertaking on the Max Planck Institute for Radio Astronomy (MPIfR). MuSES stands for Multi-messenger Research of Extragalactic Tremendous-colliders, and it is geared toward probing the AGN jets to grasp how they kind, collimate, produce neutrinos, and speed up particles.
PKS 1424+240 is a slow-moving blazar that might be one of many brightest sources of neutrinos and high-energy gamma rays ever discovered. It is also known as a BL Lacertae object, or just BL Lac, after its prototype object BL Lacertae. Bl Lacs are recognized for “large-amplitude flux variability and important optical polarization.” They’re additionally recognized for his or her virtually featureless spectra, This units them apart from different AGN that present emission traces from their sizzling gasoline.
PKS 1424+240 is billions of light-years away, and regardless of being the topic of plenty of scientific inquiry, it is nonetheless baffling. Regardless of the neutrinos and high-energy gamma photons it emits, its jet is somewhat sluggish. This goes in opposition to expectation that the quickest jets must be essentially the most energetic and the brightest.
It is taken 15 years, however astronomers utilizing the Very Lengthy Baseline Array (VLBA) in New Mexico have pieced collectively a picture of the jet on the highest-resolution ever achieved.
This determine is a VLBA stacked picture for the blazar PKS 1424+240. The contours present the Stokes stage, a technique to quantify the polarity and depth of electromagnetic radiation. Picture Credit score: Kovalev et al. 2025. A&A
“After we reconstructed the picture, it appeared completely gorgeous,” lead creator Kovalev stated in a press release. “We have now by no means seen something fairly prefer it—a near-perfect toroidal magnetic discipline with a jet, pointing straight at us.”
It seems that the jet’s aligned virtually completely with Earth, so its high-energy emissions are amplified. “Our observations uncover a uncommon situation. The item is considered contained in the jet cone, very near the axis of its relativistic jet, with a viewing angle of < 0.6°,” the authors clarify of their analysis.
Trying contained in the plasma jet cone of the blazar PKS 1424+240 with a radio telescope of the Very Lengthy Baseline Array (VLBA). The viewing angle is sort of good, permitting researchers to detect a toroidal magnetic discipline. Credit score: NSF/AUI/NRAO/B. Saxton/Y.Y. Kovalev et al. 2025. A&A
“This alignment causes a lift in brightness by an element of 30 or extra,” explains Jack Livingston, a co-author at MPIfR. “On the identical time, the jet seems to maneuver slowly attributable to projection results—a traditional optical phantasm.”
It takes a close to good alignment to have the ability to peer proper into the jet. Polarized radio alerts from the jet let the researchers map the magnetic discipline’s construction, revealing that it is probably toroidal. This construction could allow the jet to speed up particles to such extraordinarily excessive energies.
In a nod to Tolkein, the thing is named the “Eye of Sauron,” which is a potent image of Sauron’s energy. The traces of linear polarization present how we’re trying virtually instantly into the jet’s cone. Picture Credit score: Kovalev et al. 2025. A&A
“Fixing this puzzle confirms that lively galactic nuclei with supermassive black holes usually are not solely highly effective accelerators of electrons, but additionally of protons—the origin of the noticed high-energy neutrinos,” concludes Kovalev. Accelerated protons do not instantly produce neutrinos, however they’re at the start of a series of occasions that ends in neutrinos.
This animation reveals how the thing has assorted over 15 years of observations.
This analysis is a results of the NRAO’s MOJAVE (Monitoring Of Jets in Lively galactic nuclei with VLBA Experiments) observing program. MOJAVE is a long-term program to look at AGN jets that fluctuate in polarization and radio brightness. A few of its targets have been noticed for 30 years. These outcomes are precisely what MOJAVE was making an attempt to perform.
“After we began MOJAVE, the concept of someday instantly connecting distant black gap jets to cosmic neutrinos felt like science fiction. Immediately, our observations are making it actual,” says Anton Zensus, Director at MPIfR and co-founder of this system.
