Illusion, caused by gravitation In this picture of rich concentration (cluster) of Galaxies, known as Able 2218, a striking example of gravitational lensing is shown. The elongated arches across the picture, looking like a spider web, is an illusion, caused by the clusters gravitational filed. The cluster is so massive and compact that the rays of light, passing by, are distorted by its powerful gravitational field, as an optic lens distorts rays of light in order to obtain an image. As a result of this process the pictures of objects, located behind the cluster, are distorted, and the brightness of them increases. Such clusters of galaxies are “magnifying lenses” for the observation of very distant galaxies, which are impossible to be noticed with the help of big modern telescopes. The Hubble telescope has very high resolution, and this allows seeing numerous thin “arches”, and this is unachievable upon observation with the help of ground-based telescopes. ‘The arches” are distorted images of galaxies, located at the distance of 5-10 times greater, than the distance to the cluster-lens. These galaxies existed, when the age of the Universe constituted 1/4 of the current age. Studying of lensed objects might give some idea of distribution of starts formation in distant galaxies, and throws the light of early evolution of galaxies. The Hubble telescope registers such rare phenomenon, as multiplication of image. For example, systems, consisting of seven images, were registered for object Able 2218. Based on quantity of images in the area of Able 2218, caused by lensing, one can build a map of substance distribution in the center of the cluster. Some 120 weak images were registered in this picture. The study of distant galaxies, visible through well explored lenses, such as Able 2218, allows understanding the evolution of normal galaxies in the early period of the Universe. This machinery is powerful combination of capacities of a space telescope with natural focusing qualities of massive galaxies clusters. Authors: NASA Agency, Hubble space telescope, wide-angle planet Camera-2, V. Coach. |