NASA's Hubble space telescope has captured a series of stunning images of some of the universe's brightest galaxies.

Only a few dozen of these bright infrared galaxies - which are as much as 10,000 times more luminous than the Milky Way - exist in the universe.

They reside in unusually dense regions of space that somehow triggered rapid star formation in the early universe.

Hubble was able to capture the images thanks to a natural phenomenon called gravitational lensing, which occurs when the intense gravity of a massive galaxy magnifies the light of fainter, more distant background sources.

In this case, the distant galaxies have been magnified to reveal a tangled web of misshapen objects, punctuated by exotic patterns such as rings and arcs.

NASA scientists believe that the unusual forms may have been produced by spectacular collisions between distant, massive galaxies in a sort of "cosmic demolition derby".

"We have hit the jackpot of gravitational lenses," said lead researcher James Lowenthal of Smith College in Northampton, Massachusetts.

"These ultra-luminous, massive, starburst galaxies are very rare. Gravitational lensing magnifies them so that you can see small details that otherwise are unimaginable. We can see features as small as about 100 light-years or less across.

"We want to understand what's powering these monsters, and gravitational lensing allows us to study them in greater detail."

Part of the reason that the galaxies are so bright is that they are pumping out more than 10,000 new stars a year.

The star-birth frenzy creates lots of dust, which enshrouds the galaxies, making them too faint to detect in visible light. But they glow fiercely in infrared light, shining with the brilliance of 10 trillion to 100 trillion suns.

The distance of the galaxies from Earth means that the scenes captured by Hubble actually took place between 8 billion and 11.5 billion years ago, at the peak of the universe's star-making boom.

However, the galaxies' star-birth production is still 5,000 to 10,000 times higher than that of our Milky Way, raising the question of what powered the prodigious star birth.

One possible explanation is that their star-making output is stoked by the merger of two spiral galaxies.

However, Lowenthal said that computer simulations of the birth and growth of galaxies show that major mergers occur at a later epoch than the one in which these galaxies are seen.

Best photos taken by Hubble telescope

Another suggestion is that lots of gas - the material that makes stars - is flooding into the faraway galaxies.

"The early universe was denser, so maybe gas is raining down on the galaxies, or they are fed by some sort of channel or conduit, which we have not figured out yet," Lowenthal said.

The research team plans to use Hubble and the Gemini Observatory in Hawaii to analyse the details of the monster galaxies, in the hope of shedding more light on their formation.

Excerpt from:

Hubble telescope uses 'cosmic magnifying-glass' to capture stunning photos of Universe's brightest galaxies - Mirror.co.uk