Since its official launch in July, the James Webb telescope has transmitted several exciting images to the world. Now it continues to do so with an amazing picture of Einstein's almost perfect ring, a very special and rare gravitational lens. The galaxy discovered by this ring is over 12 billion light years away.
Gravity lensing occurs when the gravitational field of a very massive object distorts the space around it by diverting the light beams from the more remote object behind it. Then you can see the image of the object obtained, enlarged and distorted. Einstein rings form when the two objects considered are almost perfectly leveled, one by one, in relation to the observer. The point in the center is the galaxy ahead, and the circle around it is the distorted light of the second galaxy, which is much further.
The galaxy in question is called SPT-S J041839-4751.8. It was discovered by the Mid-InfraRed Infrastructure of the telescope, which operates in the medium infrared range.
The dynamics are similar to those of the local galaxies.
This was not the first time that James Webb was able to capture Einstein's ring SPT-S J041839-4751.8: it was initially seen by the main "Web" NIRCam device operating in the nearby infrared region. Spaceguy44 also published a color version of the image based on the telescope's open data, but it was not so clear.
The data obtained by MIRI provided a much more detailed image this time. The image uses three filters: the F1000W red filter, the F770W green filter, and the F560W blue filter. The final result published by Spaceguy44 was obtained through Astropy and GIMP processing.
Einstein's ring is a kind of extension of this distant galaxy, and computer models restore the real form of the galaxy through this "gravity mirage." SPT-S J041839-4751.8 is about 12.4 billion light years away from us when the universe was only 10 per cent of its current age. It was discovered in 2020 by the ALMA telescope, but at that time Einstein's ring had only an approximate display. Scientists expected young galaxies to be dynamically hot, chaotic and extremely unstable, but data showed that SPT-S J041839-4751.8 has a dynamic similar to that seen in the local universe.
Window to the Sunrise of the Universe
Studying galaxies at such a long distance enables us to learn more about the formation and development of galaxies, which is why gravitational lenses are of great interest to astrophysicists: they allow us to estimate the mass of remote objects, as well as the distribution of matter in the universe. And although the formation of the Einstein ring is relatively rare, it has been used repeatedly.
The first discovery of the Einstein ring was recorded in 1988 by a group of astronomers on a very large array, led by Jacqueline Hewitt, an astrophysicist from the Massachusetts Institute of Technology. After considering all possible explanations of the structure observed, they concluded that only Einstein's ring, as predicted by physicist in 1916, provided a consistent explanation.
Hubble's telescope also took some impressive pictures of Einstein's rings; however, they were not as "perfect" as Webb's recently captured ring. Last year, Einstein's new ring, discovered by Hubble, considered the galaxy at a distance of 9.4 billion light-years called GAL-CLUS-022058s; this galaxy was greatly enlarged and distorted by the lens effects.