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Einstein’s Cosmic Cross Unveils the Secrets of Dark Matter ⚡ экспресс

Original: "HerS-3: An Exceptional Einstein Cross Reveals a Massive Dark Matter Halo"
arXiv:2509.14983 · 2025-09-18 · CC BY 4.0 · ⏱ 1 min · Galaxies
A perfect mirage of four clone galaxies points to invisible mass.
Abstract

We investigated a dusty starburst galaxy HerS-3 at z=3.0607, gravitationally lensed into an “Einstein cross” with a central fifth image. 1-mm spectroscopy with NOEMA and ALMA resolved the five images and revealed a set of molecular lines with identical central velocities, confirming a single redshift. An HST F110W image showed a lensing group of four galaxies with photometric z~1.0. Lens models with only the visible galaxies fail to reproduce the observations; adding a fifth massive component (a dark halo) southeast of the brightest galaxy matches the peak, shape, and orientation of all images. The source HerS-3 is an infrared ultra-luminous galaxy, viewed nearly edge-on. The discovery offers a natural laboratory for studying nuclear star formation at the peak of stellar history in the Universe and the properties of the massive dark halo.

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Space bends under mass like a trampoline mat under a weight. This curved path of light, predicted by Albert Einstein, is called spacetime curvature. When aligned just right, a massive object acts as a cosmic magnifying glass, producing multiple images of a distant source—an Einstein cross.

Astronomers found such a cross near galaxy HerS-3, shrouded in cosmic dust and furiously birthing stars. Its light is bent by a foreground group of galaxies. Comparing colors—light analysis—confirmed that all five spots in the sky are twin copies. But trying to recreate the image using only glowing matter failed. Only by adding invisible dark matter—like an unseen weight on that same trampoline—did the model match the observations. The gravitational field revealed the presence of a colossal hidden mass where nothing shines.

Now HerS-3 has become a natural telescope, letting us peer inside a distant galaxy. We’re looking back to when the universe was just 3 billion years old—long before the Sun was born. The cross not only magnifies the stellar factory of the past but also weighs dark matter: the lens contains tens of times more of it than ordinary matter.

🎯 When perfectly aligned, a gravitational lens amplifies light hundreds of times, letting us spot galaxies 10 billion light-years away.

🎬 Sci-fi writers imagine such lenses as portals to other dimensions, but in reality they show us our own past—the birth of stars in a young cosmos.

Scientists
Christian DopplerD. B. McLaughlinDidier QuelozMichel MayorR. A. RossiterAlbert Einstein
Tags
dark matter galaxy spacetime curvature cosmic dust spectroscopy
Laws
Doppler effectgravitational lensingMaxwell's equationsPlanck's lawPlanck–Einstein relationWien's displacement law
Original: arXiv:2509.14983 · CC BY 4.0 · bridge42worlds