ESO's ALMA Detects Gas Clouds That Helped Form First Galaxies

The European Southern Observatory's Atacama Large Millimeter/submillimeter Array, more commonly referred to as ALMA, has detected the most distant gas clouds that form stars thus far discovered in the early universe. That makes this a particularly notable observation, and will allow researchers to further understand how the very first galaxies were formed and how they cleared away hydrogen gas fog during a period known as "reionization". Until this point, such observations were described as being simply "faint blobs".

ESO detailed the observation today, saying that Roberto Maiolino and his team sought to find the "faint glow" that comes from gas clouds' ionized carbon – the base upon which the stars were developing. The team also elected to look at "less dramatic" and common galaxies that eventually comprised most of the galaxies around us.

It was galaxy BDF 3299 in particular that resulted in the observations — the team picked up a glowing carbon signal, which was faint and was coming from one side of the galaxy rather than its center. This positioning, the researchers say, may be caused by the more central clouds getting disrupted by new stars.

Said the study's co-author Andrea Ferrara, "This is the most distant detection ever of this kind of emission from a 'normal' galaxy, seen less than one billion years after the Big Bang. It gives us the opportunity to watch the build-up of the first galaxies. For the first time we are seeing early galaxies not merely as tiny blobs, but as objects with internal structure!"

SOURCE: European Southern Observatory