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Remember when we told you that the massive galaxy cluster known as El Gordo is packing as much mass as 2 quadrillion suns? We lied.
New information from the Hubble Space Telescope suggests that the supermassive galaxy cluster contains as much mass as 3 quadrillion suns. Before these discoveries, El Gordo was still one of the most massive clusters in the known Universe. Other clusters near this size exist closer to Earth, but El Gordo lies 7 billion light-years away. It is believed that clusters of this mass were very rare in the early Universe.
So why the discrepancy? Researchers believe that El Gordo is actually the result of a massive collision between two galaxy subclusters. The process of merging affects the gases in the cluster as well as the motion of each galaxy, making the process of measurement difficult. In order to get an accurate picture, scientists peered around behind the massive cluster. The sheer mass of El Gordo warps the light coming from background galaxies, and by calculating this effect, known as gravitational lensing, researchers were able to come up with the new estimate of El Gordo’s mass.
The cluster is so large that it doesn’t fit within Hubble’s field of view, so a mosaic image is the next goal. Future telescopes with larger fields of view may give us even better looks at massive, distant objects like El Gordo.
Image: NASA, ESA, and J. Jee (University of California, Davis)