Evrim Yazgin
Cosmos science journalist
Astronomers have discovered a unique arrangement of distant galaxies which form an exquisitely aligned gravitational lens, magnifying deep space.
Called, the “Carousel Lens”, the configuration is detailed in a paper published in the Astrophysical Journal. It will give astronomers an opportunity to look deep into the universe and could aid in illuminating mysteries such as dark matter and dark energy.
The lens itself is made up of a cluster of galaxies about 5 billion light-years from Earth.
Gravitational lensing was first predicted by Einstein’s General Theory of Relativity. Einstein’s theory proposed that massive objects – such as stars, black holes and galaxies – warp the fabric of space time.
As a result, such objects can “bend” the path of light from objects further away to create a lens. When a gravitational lens lies between distant objects and observers on Earth, the distant objects are magnified.
Behind the Carousel Lens are 7 different galaxies which are magnified. These galaxies are between 7.6 and 12 billion light-years from Earth – at the edge of the observable universe.
“This is an amazingly lucky ‘galactic line-up’ – a chance alignment of multiple galaxies across a line-of-sight spanning most of the observable universe,” says co-author David Schlegel, a senior scientist at the Lawrence Berkeley National Laboratory in the US. “Finding one such alignment is a needle in the haystack. Finding all of these is like eight needles precisely lined up inside that haystack.”
The team found these galactic needles in a cosmic haystack using new data from the DESI (Dark Energy Spectroscopic Instrument) surveys, observations from the Hubble Space Telescope and the Perlmutter supercomputer at NERSC (National Energy Research Scientific Computing Center).
“Our team has been searching for strong lenses and modelling the most valuable systems,” explains co-author Xiaosheng Huang, from Berkeley Lab and a professor at the University of San Francisco.
“The Carousel Lens is an incredible alignment of 7 galaxies in 5 groupings that line up nearly perfectly behind the foreground cluster lens. As they appear through the lens, the multiple images of each of the background galaxies form approximately concentric circular patterns around the foreground lens, as in a carousel.
“It’s an unprecedented discovery, and the computational model generated shows a highly promising prospect for measuring the properties of the cosmos, including those of dark matter and dark energy.”
