Israeli astronomers cast new light on dark matter

Tel Aviv University researchers observed an alignment of 14 galaxies (from the lower-right to top-left), of which 13 were creating new stars (highlighted reddish points).No one knows how the universe is structured but physicists and astronomers alike believe that the thing called “dark matter” plays a central role. In physics and astronomy, dark matter and its companion dark energy, account for most of the universe’s mass. Its presence is implied in the rotation of the galaxies, their orbits in clusters and temperature distribution between them, and the evidence suggests that there is far more matter that does not interact with the electromagnetic force, meaning dark matter, than that which does. In other words, you can feel it, but you can’t see it. At least until now.

A team led by Dr. Noah Brosch, director of the Tel Aviv University’s Wise Observatory, is the first in the world to uncover what they believe are visible traces of a “filament” of dark matter, and posit that the filament is an entity on which galaxies can align, cluster and form. The research has major implications for understanding galaxy formation.

Giant soap bubbles

Brosch based the research on one accepted theory that large galaxies cluster together on structures similar to giant soap bubbles, and theorizes that a filament can originate at a point where two “bubbles” intersect.

From the Wise Observatory, Brosch, with Masters student Adi Zitrin and researchers from Cornell University in the US, studied an area of the sky opposite the constellation Virgo, where 14 galaxies were forming a line. Thirteen of these galaxies were simultaneously creating new stars.

The researchers theorized that the galaxies might be forming on a filament of dark matter that then attracts regular matter and subsequently gives forth new stars.

“There has long been a theoretical belief that this was the case,” says Brosch, “but this new finding represents experimental results that such a filament really exists, and that possibly it is an entity made from dark matter which is aligning these galaxies.”

The new grouping of galaxies to our own Milky Way galaxy is surprisingly close. Brosch says, “Our studies show that you don’t need to go to the edge of the universe to find dark matter. It may be only 15 million light years away, more or less in our backyard.”

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