A team of astronomers has succeeded in creating one of the most perfect and detailed maps of dark matter, substance, invisible and of which little is known, which makes up most of the universe. These new observations, made about a giant cluster of galaxies at 2.2 million light years away from Earth, may hold clues to the formation of the Cosmos in their early years and help in the search for an explanation of what is precisely, this dark matter, one of the central problems of modern physics and astronomy.
The team, led by Dan Coe, researcher Jet Propulsion Laboratory NASA of in Pasadena (California) used the Advanced Camera for Hubble Space Telescope to identify this invisible matter in the massive galaxy cluster Abell 1689, located 2.2 million light years and contains 1,000 galaxies and billions of stars.
Dark matter, devoid of atoms, is distributed around galaxies as irregular halos. It is undetectable in both the visible light range and the rest wavelength of the telescopes, so its existence must be inferred in other ways: in the resulting gravitational effects on other objects that we can see, as in this case, galaxy clusters. This type of evidence, we have demonstrated that dark matter is very abundant, and to make up 23% of the total mass of the universe. The known matter, which forms from a planet in a cockroach-all we see, is only a tiny 4%. The rest is dark energy, a force even more mysterious.
MIRROR LIKE A JOKE
The star cluster Abell 1689, and the rest, gravity acts as a cosmic magnifying glass, magnifying the light from distant galaxies behind it. This effect, called gravitational lensing, and expanded produce distorted images of galaxies, as when we look at one of those mirrors joke.
By studying these distorted images, astronomers estimated the amount of dark matter within the cluster. And they discovered something curious. The center of Abell 1689 is much more dense dark matter than expected for a group of its size. The results suggest that clusters of galaxies may have formed earlier than expected, before the push of dark energy that pushes galaxies apart from each other, inhibiting their growth. One of the ways that astronomers can confirm this primeval tug of war is, precisely, by mapping the distribution of dark matter in clusters.
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