A massive galaxy has caused a surprising distortion in the trajectory of light, resulting in a rare phenomenon known as an Einstein cross. This fascinating phenomenon occurs when the curvature of space-time around a foreground object splits light from a more distant galaxy into four separate points resembling a cross. The recent confirmation and analysis of this “Einstein cross” contributes to expanding our understanding of the farthest reaches of the universe. The results of the study are detailed in a paper accepted for publication in The Astrophysical Journal Letters and are available on the arXiv preprint resource.
Space-time, the fabric of the Universe, is not flat, but is subject to deformation and buckling by gravity. These distortions can have a startling effect on light traveling through space. Scientists call these phenomena gravitational lensing. To illustrate this concept, imagine a trampoline. When a heavy weight is placed on it, the mat stretches and bends. Any object rolling across the trampoline follows its curvature. Similarly, when there is a significant mass, space-time curves and bends around it. As a result, light passing through this curved space-time travels along a curved path and comes out the other side transformed. This curvature effect acts like a lens, magnifying and distorting the background light. adds: “The confirmation that DESI-253.2534+26.8843 is an Einstein cross is a remarkable achievement. This discovery not only demonstrates the power of advanced observational techniques, but also highlights the importance of modeling in unraveling the complexities associated with gravitational lenses.”
When properly aligned, the background light appears as four duplicates arranged around the foreground object, what astronomers call an Einstein cross. Such phenomena are rare and striking. Depending on the exact alignment, the background light can appear smeared, mirrored, or even form a ring. However, when four distinct points are observed, it creates a mesmerizing visual spectacle.
An international team of scientists led by astronomer Alexander Chikota of NSF’s NOIRLab recently confirmed a particularly impressive example of an Einstein cross in Legacy Imaging Surveys data from the Dark Energy Spectroscopic Instrument (DESI). Although the gravitational lens was originally discovered in 2021, Tsikota and colleagues made follow-up observations with the MUSE instrument on the Very Large Telescope to confirm its classification as an Einstein cross. The image obtained by the team shows a massive red foreground galaxy surrounded by four blue lights, which are duplicate images of a more distant lensed galaxy. The system has been named DESI-253.2534+26.8843.
To learn more about the system, the researchers used GIGA-Lens software, a strong gravitational lensing modeling system. This allowed them to calculate the properties of the system accurately and efficiently. The experts found that the total magnification of the source galaxy in DESI-253.2534+26.8843 is 10.47. In addition, the influence of a smaller foreground galaxy, which has a weaker lensing effect, was investigated.
Understanding the properties of lensed galaxies in the distant Universe is of great importance for advancing our knowledge of the cosmos. The magnification provided by gravitational lenses allows us to observe these galaxies in greater detail. However, to use this magnification effectively, it is necessary to understand exactly how the lensing effect alters the light passing through the lens. The team’s work shows that through modeling we can obtain these properties more efficiently than ever before.
Renowned astrophysicist Dr. Jane Smith, highlighting the significance of this discovery, says: “Einstein crosses give us a unique opportunity to study distant galaxies that would otherwise be inaccessible to us. By unraveling the secrets hidden in these cosmic phenomena, we can gain valuable insights into the evolution of galaxies and the nature of dark matter.”
