The James Webb Space Telescope helped scientists discover Einstein’s first zigzag. This is a quasar, a cosmic object that has been repeated six times through gravitational lensing. The effect takes its name from the fact that the term “gravitational lensing” was first proposed by Albert Einstein in 1915.

Explains why this is an important discovery and who its author is After investigating the material, 24 Channel Space.com.

What is known about Einstein’s zigzag

The system, called J1721+8842, consists of a quasar, an extremely bright galactic nucleus lensed by two galaxies. This is an incredibly rare discovery; It is an example of the interesting phenomenon of space-time distortion explained in Albert Einstein’s theory of relativity.

The first Einstein zigzag ever seen by man could help scientists solve two of cosmology’s greatest mysteries. The first mystery concerns the nature of dark energy, or the force that causes the universe to expand rapidly, accounting for approximately 70% of cosmic energy and matter. The second concerns the discrepancy that scientists discovered when measuring the value of the expansion rate of the universe, called the Hubble constant.

I’m excited not only because this is a fascinating natural phenomenon, but also because this system holds incredible promise for measuring cosmological parameters. This lensing system has the potential to place previously impossible limits on both the Hubble constant and the dark energy equation of state.
– says Martin Millon, one of the authors of the discovery and a cosmologist at Stanford University.

What is gravitational lensing?

According to the theory of general relativity, massive objects cause distortions in the fabric of space-time that coalesce into a single entity. The greater the mass of the object, the greater the distortion – a kind of “hole” it creates in space-time. Due to this distortion, gravity arises: larger objects have a stronger gravitational effect.

How a gravitational lens works / NASA, ESA and L. Calçada

Gravitational lensing occurs when light from a distant object passes by a large object that acts as a lens. It winds along different orbits around the massive body. As a result, light from the same source can reach the telescope from different directions and at different times.

This creates an effect where an object appears in multiple places in the image. This is how phenomena such as “Einstein rings”, “Einstein intersections” and “Einstein’s zigzag” in the quasar J1721+8842 arise.

Typically, gravitational lensing produced by a single galaxy creates two or four images of the source, depending on alignment. In this case, there is a unique alignment of two galaxies and a distant quasar, creating a rare configuration of six images.
Millon explained.

This configuration has been called “Einstein’s zigzag” because the orbits of the two images go around the first galaxy on one side and are then deflected by the second galaxy on the other side, creating a zigzag pattern. This discovery not only demonstrates the extraordinary beauty of the universe, but also helps study fundamental laws of physics, such as the expansion of the universe and the nature of dark energy.

The study’s lead author, Frédéric Dukes, a scientist at the Astrophysics Laboratory of the Federal Polytechnic University of Lausanne, noted that this is the first time scientists have recorded such a perfect alignment of three different objects that together form a gravitational lens. .

Usually a gravitational lens contains only two objects; for example, a galaxy acting as a lens and another galaxy behind it, whose light is bent by the foreground. Of course, there are examples of lensing that occur as a result of the simultaneous interaction of multiple galaxies, such as in galaxy clusters. But in such cases the effects of different objects are poorly combined. A single galaxy acting as a perfect lens is a very rare phenomenon because their alignments are often not accurate enough.
Dukes explained.

However, the J1721+8842 case turned out to be exceptional.

The nearest galaxy forming this lens is so distant that its light took 2.3 billion years to reach Earth. And the light from the distant galaxy flew towards us for 10 billion years.

Dukes said that despite the great distance between the two galaxies, they form such a perfect alignment that they both refract light from the quasar source, located about 11 billion light-years away, at the same time. Moreover, the closer galaxy also focuses the light from the intervening galaxy.

Quasar J1721+8842 / Observations of Frederick Dukes

“This is an extremely rare phenomenon. We estimate that only one in 50,000 lensed quasars may have this configuration… And since we only know of about 300 such quasars, we are very lucky to have found it! It is possible that we will never find it.” We will find a similar object again,” Dükler says.

How could “Einstein’s zigzag” help solve the cosmological crisis?

Frederick Dukes shared that his team is currently working on updated models of the J1721+8842 system to measure the Hubble constant.

Most lensed quasars can be used for this, but having this system with two different lenses greatly increases the accuracy of the model and therefore reduces the uncertainty in the value of the Hubble constant. This is crucial at a time when cosmology is facing a possible crisis due to Hubble stress.
– explained the scientist.

The Hubble tension arises because measurements of the Hubble constant in the early Universe and estimates of its evolution over 13.8 billion years must match measurements in the local Universe. However, these two values ​​are significantly different.

“Of course, discrepancies can be due to measurement errors. Therefore, we need to look for potential errors and improve the methodology before declaring a crisis,” Dukes added.

This unique zigzag-shaped object could help reduce measurement uncertainty and approach Hubble constant values ​​obtained by different methods. Moreover, the J1721+8842 system may also help refine the equation of state of the Universe’s dark energy.

This is important because this quantity and the Hubble constant often dissolve together, creating a so-called degeneracy. This means that both features can be adjusted in different directions while remaining within the data. But with this system we can separate these parameters.
– noted the scientist.

According to the scientist, this will be a breakthrough because determining these two values ​​simultaneously and accurately is a task that is often impossible to implement.. Although studies in this direction are currently ongoing, serious theoretical training and technical infrastructure need to be developed to prevent errors from occurring.

Additionally, J1721+8842 allows the study of a more distant galaxy that acts as both a lens and a light source. Thanks to this, scientists can accurately determine its mass, study the history of star formation and the distribution of matter. “This is the first real opportunity to answer these kinds of questions in a galaxy this distant,” Dukes said.

Although the James Webb telescope played an important role in discovering the true nature of J1721+8842, it is not an ideal tool for searching for such systems.

“JWST provides extremely deep observations of small areas of the sky. But to find objects like Einstein’s zigzag, we need large-scale surveys of the entire sky,” Dukes said. “Mission such as Gaia, Pan-STARRS, Euclid or the upcoming LSST. Research at the Vera Rubin Observatory is better suited for such missions. We will continue to search for lensing quasars, and perhaps we will find something equally unique. Good luck.”