Herschel Discovers Galaxy Merger in the Very Early Universe


What seemed at first like a rare instance of a huge, ancient galaxy revealed itself to be an even rarer pair of extremely massive galaxies, seen on the brink of merging when the Universe was only a billion years old.

This outstanding source was first identified by ESA's Herschel space observatory, which scanned the sky between 2009 and 2013, was key to finding this source. and later exposed in greater detail with the ground-based Atacama Large Millimeter/submillimeter Array (ALMA) in Chile.

The earliest galaxies in the 13.8 billion-year history of our cosmos started to take shape a few hundred million years after the Big Bang, as matter flowed towards increasingly denser spots and as the first stars were igniting into life.These two galaxies, each roughly as massive as our Milky Way, were informally dubbed the 'Horse' and the 'Dragon'. Teeming with star formation, they are 10 to 100 times more massive than most galaxies at the same epoch in the Universe's history. The Horse and the Dragon will eventually come together, giving rise to an even more massive galaxy in a few hundred million years' time.

Primordial galaxies, however, were not like the ones we are familiar with today. They started out much smaller than our Milky Way galaxy, which is now home to hundreds of billions of stars, and slowly grew more massive over billions of years.

"Scrutinising several hundred thousand galaxies observed by Herschel, we identified a very rare instance of a massive object in the very early Universe," says Dominik Riechers from Cornell University, USA, who is the lead author of the new study.

In addition, because the Universe is expanding, the wavelength of light emitted by distant galaxies is stretched even longer along its cosmic journey, up to the submillimetre in the case of the most distant galaxies, whose light was released in the first few billion years of cosmic history.

The team is now busy investigating this extreme merging system in even greater detail, studying the properties of its stellar population and dust with ALMA as well as with the European Southern Observatory's Very Large Telescope.

• ESA's Herschel space observatory.
• Europe's Atacama Pathfinder Experiment (APEX).
• Atacama Large Millimeter/submillimeter Array (ALMA).
• Europe’s Very Large Telescope (VLT).
• NASA/ESA/CSA James Webb Space Telescope (JWST), be launched in 2019, will allow astronomers to delve deeper into the secrets of this system.

Source Data: ESA. 13th November 2017

Tekdata interconnections’ Cryoconnect division have manufactured both low temperature (LT) and Ultra Low Temperature (ULT) interconnection systems for all the Space and ground based programs listed above and are proud to be involved and part of the evolving understanding of the origins of the Universe.

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