An international research team spots cluster of oversized baby galaxies enveloped in dark matter at the edge of the visible Universe. The discovery was made with help from the Chile-based Atacama Large Millimeter/submillimeter Array (ALMA) observatory, which is currently the world’s most powerful tool to study space through submillimeter light.
The authors of the discovery likened dark matter with an invisible web on which stars, planets, galaxies and all objects in the visible universe are threaded along. Dark matter remains invisible to our naked eyes because it doesn’t interfere in any way with light. But scientists know about its presence from the gravitational disturbances it exerts on space and time. Researchers believe that 85 percent of the known universe is made of the elusive matter.
The newly found galaxies are very active stellar nurseries, researchers reported. But the team was puzzled that such galaxies do not exist anymore in our times. Yet, scientists are confident that these oversized space objects can provide valuable hints on how elliptical galaxies emerged.
On the other hand, analyzing these galaxies is very challenging because they are often enveloped in dense clouds of dust and gas where new stars are born. This is why radio telescopes often fail to detect them. But ALMA is focused on submillimeter emissions of light, which made the discovery possible.
Study authors calculated the distance between a cluster of nine galaxies observed in the direction of the constellation Aquarius and compared the findings with similar observations made with ALMA’s forerunner, the Atacama Submillimeter Telescope Experiment (ASTE), and Japan’s Subaru telescope, which took a snapshot of the galactic cluster in visible light.
But the two other telescopes only indicated an approximate shape of the cluster of early galaxies. ALMA, however, detected a gravitational disturbance that scientists believe is the result of the galaxies being located within a tight knot of dark matter.
The recent discovery confirms scientists’ theory that the universe’s largest galaxies appeared within dense clouds of dark matter. The research team speculates that these baby galaxies develop and morph into elliptical galaxies, which are very frequent in the modern universe.
The findings also point that elliptical galaxies also sit within dense clouds of dark matter in their early years, and are shaped by these clouds’ tremendous gravitational force. The galaxies are located 11.5 billion light-years away and are visible from the SSA22 portion of sky in the said constellation.
A research paper on the findings was published Thursday in the Astrophysical Journal Letters.
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