Warped space creates cool kaleidoscope view of faraway galaxy.
The “funhouse mirror” has delighted carnival-goers for more than a century by twisting peoples’ images into wildly distorted shapes. Its prolific inventor, Charles Frances Ritchel, called it the “Ritchel’s Laugh-O-Graphs.” However, there was nothing funny – but instead practical – about warped images as far as Albert Einstein was concerned. In developing his general theory of relativity, Einstein imagined the universe as a grand funhouse mirror caused by wrinkles in the very fabric of space.
This recent picture from Hubble shows a galaxy nicknamed the “Sunburst Arc” that has been split into a kaleidoscope illusion of no fewer than 12 images formed by a massive foreground cluster of galaxies 4.6 billion light-years away.
This beautifully demonstrates Einstein’s prediction that gravity from massive objects in space should bend light in a manner analogous to a funhouse mirror. His idea of space warping was at last proven in 1919 by observations of a solar eclipse where the sun’s bending of space could be measured. A further prediction was that the warping would create a so-called “gravitational lens” that, besides distortion, would increase the apparent size and brightness of distant background objects.
It wasn’t until 1979 that the first such gravitational lens was confirmed. An otherwise obscure galaxy split and amplified the light of a distant quasar located far behind it into a pair of images. Far more than a space-carnival novelty, gravitational lensing observations today are commonly used to find planets around other stars, zoom in on very distant galaxies, and map the distribution of otherwise invisible “dark matter” in the universe.
Gravitational lensing means that the foreground galaxy cluster is so massive that its gravity distorts the fabric of space-time, bending and magnifying the light from the more distant galaxy behind it. This “funhouse mirror” effect not only stretches the background galaxy image, but also creates multiple images of the same galaxy.
The lensing phenomenon produces at least 12 images of the background galaxy, distributed over four major arcs. Three of these arcs are visible in the top right of the image, while one counter arc is visible in the lower left — partially obscured by a bright foreground star within the Milky Way.
The galaxy, nicknamed the Sunburst Arc, is almost 11 billion light-years from Earth and has been lensed into multiple images by a massive foreground cluster of galaxies 4.6 billion light-years away.
Hubble uses these cosmic magnifying glasses to study objects that would otherwise be too faint and too small for even its extraordinarily sensitive instruments. The Sunburst Arc is no exception, despite being one of the brightest gravitationally lensed galaxies known.
The lens makes images of the Sunburst Arc that are between 10 and 30 times brighter than the background galaxy would normally look. The magnification allows Hubble to view structures as small as 520 light-years across that would be too small to see without the turboboost from the lensing effect. The structures resemble star forming regions in nearby galaxies in the local universe, allowing astronomers to make a detailed study of the remote galaxy and its environment.
Hubble’s observations show that the Sunburst Arc is similar to galaxies which existed at a much earlier time in the history of the universe, perhaps only 150 million years after the Big Bang.
Source: Hubblesite Press Release