In 2022, James Webb Space Telescope (JWST) captures a nearly flawless Einstein ring from a galaxy 12 billion light-years away. Reddit user Spaceguy44 shared images on the platformand explained that an Einstein ring is formed when a distant galaxy is enlarged and encircled into an almost perfect ring by a massive foreground galaxy. That galaxy in the images is called SPT-S J041839-4751.8.
Now, JWST has once again captured an Einstein ring wherein mages unveil the most distant Einstein ring ever observed. This remarkable 21-billion-light-year distant halo of distorted light envelops a densely enigmatic galaxy and exhibits an extraordinary level of perfection.
What Is an Einstein Ring?
An Einstein ring is an exceedingly uncommon occurrence in the realm of gravitational lensing, initially predicted by Albert Einstein's theory of relativity. This phenomenon materializes when the immense gravitational force exerted by a substantial foreground object, such as a galaxy cluster or a black hole, distorts the very fabric of space-time enveloping it.
Consequently, when light emitted by more distant celestial objects, such as galaxies or supernovas, traverses this distorted space-time, it undergoes a transformation, assuming a curved and convoluted appearance when observed from our Earth-bound perspective.
One intriguing facet of gravitational lensing lies in its capacity to function as a natural magnifying glass, amplifying the luminosity emitted by the lensed object. This amplification empowers astronomers to scrutinize remote objects with an unparalleled level of detail, surpassing the limits of what would be feasible under ordinary circumstances.
Typically, gravitationally lensed objects materialize as arcs or partial rings encircling the foreground object. However, the most extraordinary manifestation of this phenomenon is the authentic Einstein ring, which takes shape as a complete and unblemished circle encircling the nearer celestial body.
The realization of such a flawless ring necessitates an exceptionally rare alignment of the distant object, the foreground object, and the observer.
New Einstein Ring Captured After 200 Hours of Galactic Observation
Researchers have discovered a new Einstein ring, named JWST-ER1, within the COSMOS-Web survey using the JWST. This ring is eerily circular and was found in a map of over 500,000 galaxies observed during a 200-hour JWST observation.
According to a paper in the preprint server arXiv, JWST-ER1 consists of two parts: JWST-ER1g, a foreground galaxy acting as the lensing object, and JWST-ER1r, which forms the luminous ring from a more distant galaxy. The foreground galaxy, JWST-ER1g, is about 17 billion light-years from Earth, and JWST-ER1r is an additional 4 billion light-years farther away.
The complete ring of JWST-ER1 allowed researchers to calculate the lensing galaxy's mass by measuring how it warped space-time. This revealed that the galaxy has an exceptionally dense mass, equivalent to about 650 billion suns. Some of this mass may be attributed to dark matter, but the rest remains unexplained.
Other similarly ancient and dense galaxies have been discovered, suggesting common characteristics that make them massive. Possible explanations include an abundance of dark matter or more low-mass stars compared to younger galaxies.
JWST has previously identified genuine Einstein rings, including one spotted in 2022 around the galaxy JO418, located around 12 billion light-years from Earth. The telescope has also used gravitational lensing to observe the most distant star ever detected and one of the universe's oldest galaxies, expanding our understanding of the cosmos.
RELATED ARTICLE: James Webb Space Telescope Captures Sharper Image of Einstein Ring
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