London: Astronomers have obtained the best view of merging galaxies in the distant Universe, which took place when the Universe was only half its current age, with the help NASA/ESA Hubble Space Telescope and other telescopes on the ground and in space.
They enlisted the help of a galaxy-sized magnifying glass to reveal otherwise invisible detail. These new studies of the galaxy H-ATLAS J142935.3-002836 have shown that this complex and distant object looks like the well-known local galaxy collision, the Antennae Galaxies.
These cosmic lenses are created by massive structures like galaxies and galaxy clusters, which deflect the light from objects behind them due to their strong gravity an effect, called gravitational lensing. The magnifying properties of this effect allow astronomers to study objects that would not be visible otherwise.
But for these gravitational lenses to work, the lensing galaxy, and the one far behind it, needs to be very precisely aligned. H-ATLAS J142935.3-002836 wasone of these sources and was found in the Herschel Astrophysical Terahertz Large Area Survey (H-ATLAS). It was among the brightest gravitationally lensed objects in the far-infrared regime found so far.
The Hubble and Keck images revealed a detailed gravitationally-induced ring of light around the foreground galaxy. These high resolution images also showed that the lensing galaxy is an edge-on disc galaxy similar to our galaxy, the Milky Way which obscures parts of the background light due to the large dust clouds it contains.
Rob Ivison, ESO's Director for Science concluded that with the combined power of Hubble and these other telescopes they have been able to locate this very fortunate alignment, take advantage of the foreground galaxy's lensing effects and characterize the properties of this distant merger and the extreme starburst within it.