The James Webb Space Telescope image of a Einstein ring Perfectly recorded. This attractive halo of light is the result of distant galactic light passing through the curved space-time around another galaxy that is on the path of the distant galaxy and Earth. This new image, processed by an astronomy enthusiast and published on reddit, is one of the best recorded examples of this strange astronomical phenomenon.
The ring of light in the new image comes from a distant galaxy called SPT-S J041839-4751.8 (abbreviated as J0418 in this paper), which is nearly 12 billion light-years from Earth and is one of the oldest galaxies in the Universe. J0418 is located directly behind another galaxy (the bright blue dot in the center of the ring) that is so massive that its gravity bends the space-time around it. When J0418’s light reaches the background galaxy, it moves through this curved space. From the point of view of the terrestrial observer, this light seems to be bent around the background galaxy, but in fact the electromagnetic waves have always traveled in a straight line.
This strange effect is similar to what happens in glass lenses. Similar to a magnifying lens, in this phenomenon the light from distant galaxies appears to be much closer than it really is. The only difference between these two phenomena is the replacement of glass with space-time bent by gravity. As a result, scientists call this phenomenon gravitational lensing. Albert Einstein first predicted this phenomenon when presenting the theory of relativity in 1912.
Reddit user and graduate student in astronomy with the username “Spaceguy44” posted this image of J0418 on September 1 in the r/jameswebb subreddit. Published. The anonymous astronomer used publicly available data from the James Webb Space Telescope’s Mid-Infrared Instrument (MIRI) for this image.
Galaxy J0418 in James Webb’s MIRI sensor image
“We wouldn’t be able to see J0418 without the light bending effect of gravity,” he wrote on Reddit. “Without the effect of gravitational lensing, this galaxy would probably be seen as a small bright spot like other distant galaxies.”
The new image is not our first look at J0418, but it is the most detailed image to date. Researchers identified this galaxy in 2020 using the Atacama Large Millimeter/Submillimeter Array (ALMA) in Chile. They found it in Nature magazine published and simulated the real shape of the distant galaxy.
ALMA image of Einstein ring J0418 (left) and simulated image of the real view of the galaxy (right)
On August 22 of this year, Spaceguy44 had published an image of J0418 using data from Jamesob’s NIRCam instrument, but that image was less clear and the light ring was less recognizable.
Galaxy J0418 in James Webb’s NIRCam sensor image
The Hubble Space Telescope also captured images of several Einstein rings, but none were as complete or as clear. Perfectly circular Einstein rings are extremely rare because the distant galaxy and the background galaxy must be exactly aligned as seen by the observer. James Webb’s advanced sensors will make it easier to identify these phenomena in the future.
The J0418 image is the latest example of high-quality images of the universe that the James Webb Telescope has provided to researchers and the public. Since the release of its first image in July, this space telescope has shown many spectacular images such as a stunning infrared view of the planet Jupiter, a beautiful image of the Milky Way galaxy and an amazing image of the Tarantula Nebula.