SCIENTISTS were recently shocked by the discovery of a mysterious “dark object” hidden in a space-time distortion. The object was detected as a “strange bulge” in a gravitationally distorted arc of light, and is thought to be the smallest pure clump of dark matter ever detected.
This accidental discovery could provide significant support for the theory of cold dark matter (CDM). The main model astronomers use to explain how dark matter structures the cosmos.
Detected from Einstein Ring Distortion
This object was discovered when a team of scientists, led by John McKean (University of Groningen and University of Pretoria) and Devon Powell (Max Planck Institute for Astrophysics, Germany), were observing the Einstein Ring phenomenon.
Einstein Rings are the most spectacular form of gravitational lensing, in which the massive gravity of a galaxy in the foreground bends light from distant galaxies behind it, creating a nearly perfect arc or ring of light.
“Hunting dark objects that don’t appear to emit light is definitely a challenge,” said Devon Powell.
The team used a global network of giant radio telescopes, including the European Very Long Baseline Interferometric Network, the Green Bank Telescope in the US, and the Very Long Baseline Array in Hawaii, to map detailed images of these galaxies.
Initially, the researchers intended to study compact symmetric objects (CSOs), small radio sources that usually originate from active supermassive black holes. However, data analysis using a supercomputer actually revealed an anomaly, there was an unusual “bend” in the arc of the radio emission. This curve can only be explained by the presence of another massive object located between the front galaxy and the back galaxy.
Wisps of Pure Dark Matter
Calculations show the invisible object has a mass of about one million times the mass of the Sun, but emits no light at all. Scientists then considered two possibilities, the object was a very inactive dwarf galaxy (faint dwarf galaxy), or a small lump of pure dark matter.
This object is about 10 billion light years from Earth. Its size is a hundred times smaller than similar clumps of dark matter found before.
“Given the sensitivity of our data, we expected to find at least one dark object, so our discovery is consistent with the so-called cold dark matter theory,” Powell explained. “Having found one, the question now is whether we can find more and whether the numbers will match the model.”
The findings, published in the journal Nature Astronomy and Monthly Notices of the Royal Astronomical Society, provide important clues about the minimum limit for how small clumps of dark matter can form. Can these clumps exist without having to form stars within them?
Chris Fassnacht of the University of California, Davis, emphasized how important this discovery is. “Finding low-mass objects like this is very important for studying the nature of dark matter,” he said. This success paves the way for further research to further test the cold dark matter model and ultimately unravel the universe’s greatest mysteries.” (Space/Z-2)
