We all know about the Big Bang, but the formation of the first galaxies has always been a mystery to scientists, until now. Using the Atacama Large Millimeter/submillimeter Array (ALMA) telescope, scientists have gained the ability to peer into the depths of foggy beginnings, when hydrogen gas was just starting to collect and condense into galaxies, in the first several hundred million years following the Big Bang.
ALMA TELESCOPE IS NOT A TIME MACHINE
The thing about light is that it doesn’t travel instantaneously. Travelling at about 300 million meters per second, even the darkest patches of the sky are filled with light that’s travelled so far that it actually outlived the object it originated from. This scientific fact is why the Sun as we know it from the Earth’s surface is actually the Sun as it appeared approximately 8 minutes ago.
ALMA TELESCOPE IS A TIME MACHINE
Recently, astronomers using ALMA peered far enough back in time that they were able to view galaxies existing 800 million years after the Big Bang. Ironically, this was only made possible by the light of glowing ionized carbon, emitted from the gaseous clouds giving birth to stars.
One of these early galaxies named BDF 3299 was specifically recognized by the clear signal of glowing carbon emitting from one side of the ancient galaxy.
QUALIFYING ALMA’S FINDINGS
“This is the most distant detection ever of this kind of emission from a ‘normal galaxy (sic), seen less than one billion years after the Big Bang,” exclaimed Andrea Ferrara, co-author of these new findings. “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!”
The reason for the above mentioned galaxies’ glowing side is that the normally brighter central clouds are being disrupted by the chaotic environment surrounding freshly born stars. Additionally, the carbon’s glow is actually tracing new, cold gas on its way into the stars from intergalactic space, and then the light is sent back out on its long journey to the ALMA’s dishes.
SCIENTIFIC PROGRESS
Ferrara explains further, “We have been trying to understand the interstellar medium and the formation of the re-ionization sources for many years…[f]inally to be able to test predictions and hypotheses on real data from ALMA is an exciting moment and opens up a new set of questions. This type of observation will clarify many of the thorny problems we have with the formation of the first stars and galaxies in the universe.”
