Cosmic web found with shock waves by astronomers

Cosmic webBecause galaxies, stars, and other phenomena have yet to be found, the vastness of space is still unfathomable.

For the time being, scientists can only view through the lens of technology.

The same approach was used to identify the cosmic web, a massive tangle of galaxies, gas, and dark matter that makes up the observable universe.

Scientists have observed a shock wave traveling through the strands of the cosmic web.

The discovery

Astronomers merged hundreds of thousands of radio telescope images, revealing a faint glow from shock waves that move charged particles across the magnetic fields that run across the cosmic web.

The findings were published in the journal Science Advances on February 17th.

They speculated that identifying the shock waves may help astronomers better grasp large-scale magnetic fields.

Yet, the attributes and origins are still undetermined.

While not involved in the research, Marcus Brüggen, an astrophysicist at the University of Hamburg in Germany, said the result allows astronomers to corroborate what simulations had shown, namely the existence of shock waves.


Contrary to popular belief, galaxies are not evenly distributed.

Instead, ropy threads of dark matter, dilute gas, and galaxies connect them in huge clusters separated by mainly empty spaces.

Tugged gravity, merging galaxy clusters, colliding filaments, and gas from falling voids populate filaments and clusters.

During cosmic web simulations, massive shock waves are generated in and along filaments on a regular basis.

Although cosmic webs are mostly made up of filaments, they are more difficult to locate than galaxies.

Shock waves

Although scientists previously identified shock waves throughout galaxy clusters, Reinout van Weeren of Leiden University in the Netherlands asserts that filament shocks have never been observed before.

“But they should be basically all around the cosmic web,” said van Weeren.

Charged particles are accelerated through filament shock waves by magnetic fields that span the cosmic web.

If this occurs, particles produce light at frequencies visible only to radio telescopes.

The signals, on the other hand, are usually fairly feeble.

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Building the image

Tessa Vernstrom, a radio astronomer at Australia’s International Centre for Radio Astronomy, emphasized that a single shock wave in a filament could not be detected.

“It’d look like noise,” she added.

Tessa Vernstrom and her colleagues integrated radio images from over 600,000 pairs of galaxy clusters that were close enough to be connected by filaments that might form a single “stacked” image.

It boosted the weaker signals, revealing a faint radio light emanating from the filaments connecting the clusters.

“When you can dig below the noise and still actually get a result – to me, that’s personally exciting,” said Vernstrom.

Regardless of its ambiguity, the signal is very contentious.

It also implies that radio waves are usually aligned with one another.

Shock waves

Highly polarized lights, according to van Weeren, are an uncommon event that can be accounted for by radio light produced by shock waves.

“So that’s really, I think, very good evidence for the fact that the shocks are likely indeed present.”

Moreover, the most recent discovery exceeds the confirmation of cosmic web modeling assumptions.

Polarized radio emissions can give an indirect view of the magnetic fields that run across the cosmos.

“These shocks are really able to show that there are large-scale magnetic fields that form [something] like a sheath around these filaments,” said Marcus Brüggen.

The origins of magnetic fields are still unknown, according to Brüggen, Reinout van Weeren, and Tessa Vernstrom.

The roles of fields in the development of the cosmic web are likewise unknown.

“It’s one of the four fundamental forces of nature, right? Magnetism,” said Vernstrom.

“But at least on these large scales, we don’t really know how important it is.”