Astronomers Detect Hydrogen in Galaxy More Than 5 Billion Light-Years Away

In a first, an international team of scientists has detected a faint signal emitted by hydrogen gas in a galaxy more than five billion light years away almost double the previous record.

Using the Very Large Array radio telescope of the National Radio Astronomy Observatory in the US, the team observed radio emission from hydrogen in a distant galaxy and found that it would have contained billions of young, massive stars surrounded by clouds of hydrogen gas.

As the most abundant element in the universe and the raw fuel for creating stars, hydrogen is used by radio astronomers to detect and understand the makeup of other galaxies.

However, until now, radio telescopes have only been able to detect the emission signature of hydrogen from relatively nearby galaxies.

"Due to the upgrade of the Very Large Array, this is the first time we've been able to directly measure atomic hydrogen in a galaxy this far from Earth," said lead author, Dr Ximena Fernandez from Rutgers, the State University of New Jersey.

"These signals would have begun their journey before our planet even existed, and after five billion years of travelling through space without hitting anything, they've fallen into the telescope and allowed us to see this distant galaxy for the very first time," he added.

The success for the team comes after the first 178 hours of observing time with the Karl G. Jansky Very Large Array (VLA) radio telescope for a new survey of the sky called the 'COSMOS HI Large Extragalactic Survey' or CHILES.

Once completed, the CHILES survey will have collected data from more than 1,000 hours of observing time.

In a new approach, members of the team including Dr Attila Popping from International Centre for Radio Astronomy Research and the ARC Centre of All-sky Astrophysics (CAASTRO) in Australia are working with Amazon Web Services to process and move the large volumes of data via the "cloud".

"For this project, we took tens of terabytes of data from the Very Large Array and then processed it using Amazon's cloud-based servers to create an enormous image cube, ready for our team to analyse and explore," Dr Popping added.

Professor Andreas Wicenec, head of the Data Intensive Astronomy team at the International Centre for Radio Astronomy Research, said the limiting factor for radio astronomers used to be the size of the telescope and the hardware behind it.

"It's fast becoming more about the data and how you move, store and analyse vast volumes of information," he said in a paper published in the Astrophysical Journal Letters.