Is our universe really part of a cosmic web?

MAUNA KEA, Hawaii (KHON2) — It has been described like rivers feeding oceans. The universe has streams of gas that nourish galaxies throughout the cosmos.

But scientists said that these streams, which make up a part of the so-called cosmic web, are extremely faint and difficult to see.

First, you probably need to know that a few years ago, astrophysicists discovered that the universe exists within a plasma state. That’s right. The universe is made of up of space plasma.

Scientists have found that plasma makes up 99.9% of the observable universe. Now, keep in mind that this is completely different from plasma that is in our blood. These scientists are talking about a state of matter, that’s similar to a gas but with different properties.

And this plasma flows through our universe. But on top of this existence is the discovery of the cosmic web.

Astronomers have known about this cosmic web for decades, and they even got a glimpse of its glow from its filaments that are around bright cosmic objects which are called quasars. Yet, they have not been directly imaged since they exist in the extended structure in the darkest portions of space. That is until now.

The Keck Observatory has announced that a team of CalTech led astronomers have captured direct images of the cosmic web for the very first time.

A Caltech-led team of astronomers were the very first to captured direct images of the cosmic web using the W. M. Keck Observatory’s Keck Cosmic Web Imager on Maunakea.

“We chose the name Keck Cosmic Web Imager for our instrument because we were hoping it would directly detect the cosmic web,” says Martin, who is also the director of the Caltech Optical Observatories, which includes Caltech’s portion of Keck Observatory. “I’m very happy it worked out.”

The team of astronomers were successfully able to detect light from hard-to-see gas filaments in a region of the cosmic web that is located 10.5 billion light-years away from Earth. These faint streams of wispy gas are known to nourish galaxies.

Understanding the cosmic web is important to the study of how galaxies are formed and how they evolve.

In our universe, galaxies tend to condense out of swirling clouds of gas. In turn, that gas then further condenses into the stars that we see in our night sky. This makes these galaxies visible, within a range of wavelengths of light, to telescopes.

Astronomers have described this web as cold, dark filaments in deep space that snake their way through the galaxies, supplying them with gas. This keeps the system of forming stars active.

Martin and his colleagues found smoking-gun evidence in 2015. Martin described it as this so-called cold-flow model of galaxy formation. Based on his description, it was believed to be a long filament funneling gas into a large galaxy. Now, his team has seen what Martin described.

“Before this latest finding, we saw the filamentary structures under the equivalent of a lamppost,” said Martin. “Now we can see them without a lamp.”