Space Scientists Discover Initial Occurrence of "Einstein Zig-Zag" Pattern, Potentially Unraveling Cosmic Expansion Enigma
An initially assumed celestial beacon in space, initially thought to be a galaxy warping light from a distant hyperactive galactic center, has been determined to be a unique and unparalleled gravitational lens, as per a research group that examined the setup.
The setup is named J1721+8842, and was initially detected in 2017. At the time, the setup was presumed to be a galaxy distorting the light of a distant quasar—an intense galactic core. However, following two years of monitoring with the Nordic Optical Telescope—alongside data from the James Webb Space Telescope—the most recent team argues that the item is actually a compound lens, comprised of two aligned galaxies. Moreover, the team argues that light traversed the lens in an undulating pattern. The team's study is currently available on the preprint server arXiv, and it proposes that the unusual architecture could provide answers to some fundamental cosmic questions.
“In this letter, we present proof from the light curves gathered at the Nordic Optical Telescope (NOT), new redshift readings from the James Webb Space Telescope (JWST) Near InfraRed Spectrograph (NIRSpec), and updated lens models, which unequivocally support the premise that a single source is lensed in J1721+8842,” the team penned.
Gravitational lenses are objects possessing adequate gravitational fields that manipulate light originating from other sources in the cosmos. Gravitational lensing was suggested by Einstein as far back as 1912.
Gravitational lenses are valuable to astronomers because they amplify distant light that would otherwise be too faint to discern. Essentially, gravitational lenses serve as entryways into extremely distant and antiquated parts of the universe; in 2022, astronomers utilized a gravitational lens to identify Earendel, the oldest-known star.
A graphic displaying the source and double lens of the system. Graphic: Dux et al. 2024
Sometimes, gravitational lenses produce rings of light in the sky, known as Einstein rings. Last year, one team posited that some Einstein rings bolstered the argument for axions in physicists’ quest to identify the phenomena responsible for dark matter, the 27% of the universe that we know to be present but cannot directly witness.
Earlier this year, a team from Lawrence Berkeley National Laboratory identified a stunning gravitational lens constructed from a configuration of galaxies that they described as the equivalent of “eight needles meticulously aligned” in a haystack. Within that lens was an Einstein Cross, which suggested the symmetric distribution of mass (including dark matter) across the lens.
Unlike prior gravitational lenses, though, J1721+8842’s structure indicates that light in the lens followed a zigzag pattern through the two galaxies; hence, the first-ever “Einstein zigzag lens.”
“Comprehensive lens models, time-delay measurements, and cosmological constraints derived from this system will be published in follow-up papers as part of the TDCOSMO collaboration,” the researchers added. This means the double lens system can aid astrophysicists’ comprehension of the Hubble constant, the number that describes the rate of the universe’s expansion. The constant is different depending on how it’s calculated, a problem known as the Hubble tension.
Being able to examine the compound lens for a new measurement of the Hubble constant will aid astronomers in understanding whether the figure aligns with the cosmological model or not. The team mentioned that the lens “can also constrain the ratio of distances between the observer, the lens, and the two sources, enabling a precise measurement of the expansion history of the Universe.”
Advanced telescopes are a testament to modernity and can help answer some of humanity’s most fundamental questions—where did everything come from, and where are we headed, for instance. But gravitational lenses make the telescopes’ task easier, by allowing the principles of gravitation to boost some of the more remote realms of our universe. Besides the insights they provide, the lenses merit acclaim in their own right. J1721+8842 is an Einstein zigzag in space—I mean, that just sounds cool as hell.
The unique gravitational lens, named J1721+8842, has been found to create an undulating pattern for the light it traverses, which the team believes could provide answers to fundamental cosmic questions in the future. With the compound lens structure, astronomers may be able to obtain a new measurement of the Hubble constant, helping to resolve the ongoing Hubble tension.
