The radio telescope was used to observe star-forming galaxies from the early universe

Mar 14, 2013 17:41 GMT  ·  By
Some of the farthest galaxies were seen with help from gravitational lensing
   Some of the farthest galaxies were seen with help from gravitational lensing

The Atacama Large Millimeter Array has just been inaugurated, but it's already being used to peek further into the universe than ever before. Just one day after its inauguration, astronomers have published a paper describing star formations in early galaxies, seen with ALMA.

Astronomers found that active periods of star formations happened much earlier than they thought, one billion years before previous estimates, just two billion years after the universe was created.

In those days, galaxies were much more packed together and contained a lot more material (gas and dust). As a result, stars were created faster and bigger than the stars of today.

These stars shun bright, but most of their light, in the ultraviolet and blue end of the visible spectrum, was absorbed by all the dust around them. But this heated up the dust making it glow in infrared.

Because of the huge distance this infrared light has traveled to reach us, due to redshift, it arrives as electromagnetic radiation in the radio spectrum, which is exactly what ALMA was designed to see.

This made it possible to spot several galaxies much further than any before, some of the galaxies observed are 12 billion years old.

Two of them are the most distant ever observed, the oldest dates to when the Universe was one billion years old, 12.77 billion years ago.

Not only were these distant galaxies seen, ALMA was also able to detect water molecules in them, indicating that water existed in the early universe, much earlier than ever seen before.

All of this was possible using just 16 of the 66 antennas that make up ALMA. At the inauguration, only 50 of them are operational. When ALMA is fully operational, it should be able to see galaxies from the very beginning of the universe, the very first galaxies and stars ever created.