Webb spotlights gravitational arcs in ‘El Gordo’ galaxy cluster (NIRCam image, annotated)

A new image of the galaxy cluster known as “El Gordo” is revealing distant and dusty objects never seen before, and providing a bounty of fresh science. The infrared image, taken by the NASA/ESA/CSA James Webb Space Telescope, displays a variety of unusual, distorted background galaxies that were only hinted at in previous NASA/ESA Hubble Space Telescope images.

El Gordo is a cluster of hundreds of galaxies that existed when the universe was 6.2 billion years old, making it a “cosmic teenager.” It’s the most massive cluster known to exist at that time. (“El Gordo” is Spanish for the “Fat One.”)

El Gordo acts as a gravitational lens, distorting and magnifying the light from distant background galaxies. Two of the most prominent features in the image include the Thin One, located just below and left of the image center, and the Fishhook, a red swoosh at upper right. Both are lensed background galaxies.

[Image description: In the center is a near-infrared image of a field of galaxies and a handful of stars. At lower left are compass arrows indicating the orientation of the image on the sky. The east arrow points toward 9 o’clock. The north arrow points twoard 12 o’clock. At the bottom right is a scale bar labeled 800,000 light-years and 240,000 parsecs. The length of the scale bar is about one sixth of the total image. Below the image is a color key showing which NIRCam filters were used to create the image and which visible-light color is assigned to each filter. NIRCam Filters from left to right: F115W and F150W are blue; F200W and F277W are green; F356W and F444W are red.]

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