Astronomers Observe Interiors of Ancient Galaxies

Data obtained using the European Southern Observatory's Alma telescope in Chile has given astronomers their first glimpse at the interior of distant galaxies, the ESO said.

Observations from the Atacama Large Millimeter/submillimeter Array (Alma) allowed astronomers to start to see how the first galaxies arose and how they cleared the cosmic fog during the era of reionization, according to an article in the Monthly Notices of the Royal Astronomical Society.

"This is the most distant detection ever of this kind of emission from a 'normal' galaxy, seen less than 1 billion years after the Big Bang," study co-author Andrea Ferrara said.

"For the first time, we are seeing early galaxies not merely as tiny blobs, but as objects with internal structure."

A team of astronomers led by Cambridge University's Roberto Maiolino trained the Alma array on galaxies that were known to be seen only about 800 million years after the Big Bang, the explosion that scientists believe gave birth to the universe.

The astronomers were not looking for the light from stars, but instead for the faint glow of ionized carbon coming from the clouds of gas from which the stars were forming.

"They concentrated on rather less dramatic, but much more common, galaxies that reionized the Universe and went on to turn into the bulk of the galaxies that we see around us now," the ESO said.

The telescope was able to detect a faint but clear carbon signal of intense brightness in a galaxy designated as BDF2399.

Alma is an international partnership of the ESO, the US, Japan, Canada, Taiwan and South Korea, in cooperation with Chile.

Alma, the largest astronomical project in existence, sits on the Chajnantor plateau, 5,000 metres above sea level.