The cluster of galaxies "El Gordo" was weighed by the Hubble Space Telescope NASA. This is the largest cluster of galaxies seen in the distant universe. It was cataloged ACT-CL J0102-4915. His nickname, El Gordo, which means "the fat" in Spanish.
It is through the distorted galaxies distant background, a team of astronomers calculated the mass of the cluster, about 43 percent more massive than previous estimates. The cluster weighs as much as 3 million billion times the mass of our Sun. This cluster of galaxies is 9.7 billion light years from our solar system. The immense gravity of the cluster subtly distorts space and the images of background galaxies, as a distorting mirror. More important is the deformation, more the cluster is massif. A fraction of this mass is enclosed in hundreds of galaxies, which populate the cluster and a larger fraction is still in the hot gas which fills the entire volume of the cluster. The rest is related to dark matter, an invisible form of matter which constitutes the essential of the mass of the universe.
« What I mostly watched these are the forms of background galaxies that are further away than the cluster itself », explained lead author James Jee of the University of California at Davis.
Although clusters of so massive galaxies are also in this part of the universe, as the cluster of the ball, nothing like this has ever been discovered so far in the time when the universe was about half of its current age, i.e. 6.85 billion years.
The immense size of the cluster El Gordo was reported for the first time in January 2012. At the time, astronomers had estimated its mass based on observations made by the Chandra X-ray Observatory NASA and velocities of galaxies measured by the Very Large Array Telescope of the European Southern Observatory in Paranal, Chile.
To obtain an independent estimate of the mass, they used Hubble and developed estimates of the cluster mass, based on the motions of galaxies moving within the group and the temperature of the hot gas between these galaxies.
To do this, they looked as if El Gordo was the result of a titanic collision between a pair of clusters of galaxies. However, the mass of the cluster El Gordo could be even greater because the giant El Gordo does not fit fully in the field of view of Hubble. Another mosaic of images to be captured, it will be the next step for the Hubble team.
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Image: The most massive clusters of galaxies ever observed, this mosaic of Hubble shows the cluster called El Gordo (fat in Spanish). The cluster contains hundreds of galaxies in this picture but there are many more because some are seen several times distorted by gravitational lensing. They spread out in a circle but that are multiple views of a single galaxy. Credit Image: NASA, ESA, and J. Jee (University of California, Davis).