Last December, Hubble took a photo of a distant galaxy that, thanks to a gravitational lens, appeared almost like a perfect “Einstein ring”. A year later, astronomers revealed what they learned by examining the image.
NASA called the image a “fused ring” galaxy because of what it looks like because of the effects of gravitational lenses. More precisely, the phenomenon shown in the image including an “Einstein ring” is called. An Einstein ring is created when light from a galaxy, group of galaxies, or star passes a massive object as it moves in line with Earth. Due to what is called the gravitational lens, light is deflected thanks to gravity, which makes it appear as if it is coming from two different places. If the object, gravity and observation unit are perfectly aligned, the light appears as a ring.
Gravitational lenses are a phenomenon that allows astronomers to see great distances without having to use the large and complex hardware that would normally require it. PetaPixel has a detailed explanation of the process from a previous article, but in short, gravity distorts space in such a way that it creates an “optics” that channels light towards a telescope – in this case Hubble – and allows it to see galaxies which is usually too far away to be studied with current technology and physical telescopes. NASA describes it as akin to looking through a giant magnifying glass.
When NASA originally released the photo of the galaxy — called GAL-CLUS-022058s — it described it as a strange and very rare phenomenon.
“GAL-CLUS-022058s is the largest and one of the most complete Einstein rings ever discovered in our universe. The object has been nicknamed by astronomers who studied this Einstein ring as the ‘Melted Ring’, alluding to its appearance and host constellation, “NASA wrote.
Now NASA has said that after examining the image and examining it more closely, astronomers were able to measure the galaxy’s distance from Earth as 9.4 billion light-years, placing the galaxy in the highest epoch of star formation in cosmic evolution.
“The extremely high star formation in the clearest and very dusty early galaxies saw stars being born at a speed a thousand times faster than what happens in our own galaxy. This could help explain the rapid build-up of today’s gigantic elliptical galaxies, ”NASA explains.
Astronomers were able to calculate that the galaxy’s light was magnified by a factor of 20.
“This magnification, amplified by Mother Nature, effectively made Hubble’s observational equivalent to a 48-meter (157-foot) telescope. The lensing effects also create more appearances around the curved arc in the single background-enlarged galaxy, ”NASA continues.
Astronomers accurately modeled the impact of lenses on the galaxy’s image to derive its physical properties.
“Such a model could only be achieved with Hubble imaging,” explained lead researcher Anastasio Díaz-Sánchez of the Universidad Politécnica de Cartagena in Spain. “In particular, Hubble helped us identify the four duplicate images and star clusters in the lensed galaxy.”
Photo credits: ESA / Hubble & NASA, S. Jha; Recognition: L. Shatz