Hubble Space Telescope Captures Best View Yet of Colliding Galaxies in Early Universe

The NASA Hubble Space Telescope has captured the best view yet of two colliding galaxies that merged when the universe was only half of its current age. The latest image reveals a bit more about how these events occur in our universe.

The new details of the colliding galaxies are seen thanks in part to a galaxy-sized magnifying glass-something called gravitational lensing. Astronomers combined the power of many telescopes on Earth and in space with a vastly larger form of lens, a cosmic lens that was created by a larger structure in the foreground magnifying the galaxies behind it.

"While astronomers are often limited by the power of their telescopes, in some cases our ability to see detail is hugely boosted by natural lenses, created by the universe," said Hugo Messias, lead author of the new study, in a news release. "Einstein predicted in his theory of general relativity that, given enough mass, light does not travel in a straight line but will be bent in a similar way to light refracted by a normal lens."

In this case, the researchers employed H1429-0028, one of the brightest gravitationally lensed objects in the far-infrared regime. After using telescopes to get different angles of the object, the scientists spotted a detailed gravitationally-induced ring of light around the foreground galaxy. In addition, they saw that the lensing galaxy was an edge-on disc galaxy, which obscures part of the background light.

The scientists further characterized the object with ALMA, which traced carbon monoxide. This revealed that the lensed object is indeed an ongoing galactic collision forming hundreds of near stars each year.

"With the combined power of Hubble and these other telescopes we 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," said Rob Ivison, one of the researchers. "It is very much a testament to the power of telescope teamwork."

The findings are published in the journal Astronomy & Astrophysics.