# Centaurus A jet simulation reproduces bright edges with field-aligned electrons, matching EHT data

- Published: 2026-11-13 06:47 UTC
- Section: Sky & Space › Astronomy
- Tags: Centaurus A jet, limb brightening, synchrotron radiation, Event Horizon Telescope, ALMA polarization, magnetic field lines, relativistic jets, active galaxy, jet simulation, black hole shadow
- URL: https://realtech.media/news/rt-9aa63fb1f4212698e8595fad_centaurus_a_jet/

**A simulation of the Centaurus A jet gives bright edges and a darker centre when electrons move along magnetic field lines. The model matches the main EHT features.**

![Centaurus A jet simulation reproduces bright edges with field-aligned electrons, matching EHT data](https://realtech.media/media/2026/11/fb98d9dcb9dc83ca.webp)
*lomazoma.com*

Researchers at JMU used a simulation to explain why the jet of the active galaxy Centaurus A appears brighter at its edges than at its centre, according to lomazoma.com. The team compared the model with Event Horizon Telescope (EHT) measurements and with polarization data from the Atacama Large Millimeter/submillimeter Array (ALMA) [1]. In the model, the bright edges arise from the behaviour of high-energy electrons, without a particularly dense outer plasma layer [1].

## Electrons along magnetic field lines

The key assumption concerns the high-energy electrons. If they move preferentially along magnetic field lines rather than randomly in all directions, the emitted synchrotron radiation depends strongly on the orientation of the local magnetic field [1]. Synchrotron radiation is what fast charged particles produce in magnetic fields. Because field lines in the jet can be helical, the model yields a luminous rim and a comparatively dark centre [1].

The simulation therefore produces an image similar to the radio observations. This offers a possible explanation of why the centre of the jet looks weaker [1].

## Comparison with observations

The team converted its simulations into artificial telescope data and fitted them statistically to EHT measurements. The model reproduces the bright edges of both the jet and the weaker counterjet and agrees with the main features of the observations [1]. The best fit gives a mass of about 60 million solar masses and a viewing angle of about 72 degrees to the jet axis; both values depend on the underlying model assumptions [1].

Calculation and observation are not identical. The computed dark zone in the centre is less pronounced, and at certain telescope baselines the measurement and the model differ [1]. Other processes, such as different flow velocities or cooling of the electrons, may also contribute to the bright edge [1]. A matching brightness pattern alone does not prove that the electrons move as assumed [1].

The calculations also make predictions for future telescopes. Measurements at higher frequencies and over shorter time intervals will show whether the model describes the time evolution and polarization of the jets correctly [1]. At about three terahertz, the simulation predicts that the shadow of the central black hole could become visible, which would require much higher angular resolution than current systems offer [1].

"Centaurus A is our closest look into the physics of relativistic jets," says Felix Glaser. Christian M. Fromm of JMU calls it astonishing that microscopic plasma effects can shape structures on much larger scales [1]. Additional measurements are needed to show whether the explanation applies to the jets of other active galaxies.

## Sources

1. [lomazoma.com](https://lomazoma.com/schwarzes-loch-gerichtete-elektronen-koennen-helle-kanten-kosmischer-jets-erklaeren-geschwindigkeitsunterschiede-und-elektronenkuehlung-koennten-ebenfalls-zur-hellen-kante-beitragen)

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Source: RealTech, realtech.media — https://realtech.media/news/rt-9aa63fb1f4212698e8595fad_centaurus_a_jet/