Astronomers Find Strands of 'Cosmic Web' that Hold Galaxies

Astronomers have found gas strands that hold galaxies in a cosmic web.

The team of astronomers, led by researchers at the University of California, Santa Cruz, found a distant quasar (hyperactive galaxies) that was illuminating a nebula of diffuse gas. Researchers believe that this bright nebula of gas, extending 2 million light-years across intergalactic space, could be the web holding all the cosmic matter.

"This is a very exceptional object: it's huge, at least twice as large as any nebula detected before, and it extends well beyond the galactic environment of the quasar," said Sebastiano Cantalupo, first author of the paper and a postdoctoral fellow at UC Santa Cruz, according to a news release.

The filament of the cosmic web was found using 10-meter (33 feet) Keck I telescope at the W. M. Keck Observatory in Hawaii.

What is a Cosmic Web?

Leading theories on the structure of Universe say that galaxies are hanging at the ends of a vast "cosmic web." About 85 percent of this cosmic web matter is the invisible dark matter.

In 2009, researchers at European Southern Observatory (ESO) had reported seeing part of this cosmic web.

Then in October 2012, researchers from France said that they've carried out a three-dimensional study of a cosmic filament of dark matter. Their calculations had shown that the cosmic web must be responsible for half of the mass of the universe.

The cosmic filament found in the current study is part of the cosmic web that keeps the galaxy, including our Milky Way together. Researchers hope to study this filament to understand the structure and development of the Universe, National Geographic reported.

How did they find it?

Quasars or "qausi-stellar radio sources" are the bright centers of very distant galaxies. In the present research, astronomers studying the quasar 'UM287' found that it was illuminating a gas filament.

"The light from the quasar is like a flashlight beam, and in this case we were lucky that the flashlight is pointing toward the nebula and making the gas glow. We think this is part of a filament that may be even more extended than this, but we only see the part of the filament that is illuminated by the beamed emission from the quasar," said Cantalupo, according to National Geographic.

The study is published in the journal Nature.