A Molten Galaxy Einstein Ring

© ESA/Hubble & NASA, S. Jha; Processing: Jonathan Lodge

It is difficult to hide a galaxy behind a cluster of galaxies. The closer cluster's gravity will act like a huge lens, pulling images of the distant galaxy around the sides and greatly distorting them. This is just the case observed in the featured image recently re-processed image from the Hubble Space Telescope. The cluster GAL-CLUS-022058c is composed of many galaxies and is lensing the image of a yellow-red background galaxy into arcs seen around the image center. Dubbed a molten Einstein ring for its unusual shape, four images of the same background galaxy have been identified. Typically, a foreground galaxy cluster can only create such smooth arcs if most of its mass is smoothly distributed — and therefore not concentrated in the cluster galaxies visible. Analyzing the positions of these gravitational arcs gives astronomers a method to estimate the dark matter distribution in galaxy clusters, as well as infer when the stars in these early galaxies began to form.

Based on Astronomy Picture Of the Day.