Einstein’s Ring that opens a window to a young universe

The Universe still has great mysteries about cosmological history that astrophysicists try to decipher every day. But among the most astonishing objects, perhaps those that distort space-time so much as to open a window into the cosmic past, are among the most astonishing for researchers, since they allow them to delve millions of years into the universal past. These are the Einstein Rings that the Hubble Space Telescope is capable of capturing and the largest and most complex ring was recently discovered, which shows us the Universe as it was 9.4 billion years ago.

What is an Einstein Ring?

Albert Einstein came to revolutionize the perception of the Universe and everything that lies in it, thanks to his General Theory of Relativity. After Einstein came to break with what was believed until then about gravity, the researchers’ perspective changed completely. The German physicist taught us that gravity works like a strange ‘glue’ that shapes the cosmos as if it were plasticine. And he introduced a concept without which we would not be able to understand the operation of this strange ‘glue’; he taught us about space-time.

Image: Hubble Space Telescope

Bearing in mind that the mass of the bodies is capable of deforming space-time and that the curvature of said element is capable of diverting the path of light, Einstein thought of the so-called gravitational lenses. They occur when the mass of an object is such that it causes the curvature of space-time, therefore, the light that travels through that section of the cosmos will also be curved. The result is an Einstein Ring, named after him, which shows us a window into the past.

A window into the early Universe

Recently the Hubble Space Telescope captured an Einstein Ring, but not just any, but the largest and most complex detected so far. It is about the Molten Ring GAL-CLUS-022058s, within the constellation of Fornax. This lens increases the visibility of distant lights and allowed the discovery of a galaxy through it. However, since the curvature of space is such that it has bent the light from said galaxy, it means that what we see from Earth has taken millions of years to reach us. That is, we are looking into the past of that mysterious galaxy.

Image: Einstein’s ring GAL-CLUS-022058s. Hubble Space Telescope

A team of astronomers from the Polytechnic University of Cartagena discovered that the galaxy that can be observed through GAL-CLUS-022058s, goes back to exactly 9.8 billion years ago. And taking into account that the Universe is 13.8 billion years old, it means that Einstein’s Ring allows us to observe a very young Universe. A window into the past that could help scientists unlock the secrets of the early Universe.

The astronomers led by Anastasio Díaz discovered that the galaxy located behind the gravitational lens corresponds to a time in the cosmos where stars were born at a rate of 70 to 170 solar masses per year. This is a rate a thousand times faster than what happens within our own galaxy. More research is needed in this regard, but for now the information obtained could help explain the rapid accumulation of giant elliptical galaxies today.

References: Diaz, A. Dannerbauer, H. Iglesias, S. Rebolo, R. (2021). The Einstein ring GAL-CLUS-022058s: a Lensed Ultrabright Submillimeter Galaxy at z=1.4796. The AstrophysicalJournal. 919. (1). DOI

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