Astronomers Capture the Birth of the Universe’s First ‘Normal’ Galaxies

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

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Jul 27 2015, 10:00am

Image: ESO/R. Maiolino

We are entering a golden age of astronomical observation, ushered in by massive ground telescopes and sophisticated space observatories. These next-generation facilities are already capturing the universe in unprecedented detail, as evidenced by this composite image produced jointly by the Atacama Large Millimeter Array (ALMA) and the Very Large Telescope, both located in Chile.

These distant spatterings of light are actually the first normal galaxies to emerge in the universe, roughly 800 million years after the Big Bang. While scientists have previously detected very bright objects like quasars from this period, this is the first time that the standard run-of-the-mill galaxies that make up the bulk of the modern universe have been witnessed in this detail, at such an early age.

One galaxy, named BDF 3299, is noticeably illuminated by an eerie orange glow, which is a result of rapid star birth. The unusual glowing effect is generated by carbon clouds that are sculpted by the unstable environment of energetic radiation and supernovae.

"For the first time we are seeing early galaxies not merely as tiny blobs, but as objects with internal structure!" said astrophysicist Andrea Ferrara, who was on the team that captured this image, in a statement.

"This study would have simply been impossible without ALMA, as no other instrument could reach the sensitivity and spatial resolution required," added team lead Roberto Maiolino.

"Although this is one of the deepest ALMA observations so far it is still far from achieving its ultimate capabilities," Maiolino said. "In future ALMA will image the fine structure of primordial galaxies and trace in detail the build-up of the very first galaxies."