The First Stars Shine at Cosmic Dawn
The First Stars Shine at Cosmic Dawn
Astronomers this week revealed findings supporting the theory that stars first appeared almost 180 million years after The Big Bang, initiating the period in our galaxy known as the Cosmic Dawn.
Spending almost a decade on their experimental investigation, astronomers sought to pinpoint when stars first brought light into our galaxy, and they did so on an instrument no larger in size than the average kitchen table.
The surprisingly primitive looking apparatus used to detect the first stars named the Experiment to Detect the Global Epoch of Re-ionization Signature (EDGES), placing the equipment in Remote Western Australia, astronomers were certain interference from man made radio waves on earth would be extremely limited on account of the remote destination.
Astronomers knew that an experiment of this nature would need to be completely free of any radio wave disturbances because astronomers were effectively looking for a radio wave that amounted to 0.01% per cent of all the radiation in our galaxy, a cosmic needle in a haystack.
A perfect comparison would be to listening to an insurmountable variety of white noise on your radio and identifying which one momentarily differed in volume, and doing this for nearly ten years.
There was no ‘let there be light’ moment following the ‘Big Bang’, no galaxies, no black holes, no supernova, known as the Cosmic Microwave Background, all that existed was Hydrogen gas in an infinite sea of background radiation. For millions of years this persisted until gravity began to crush the hydrogen together, creating concentrated hydrogen clouds, which then began to collapse resulting in the first stars forming, and over time, the eventual formation of the universe.
The first stars disappeared as quickly as they appeared but in doing so absorbed radiation present following the Big Bang, radiation that astronomers predicted would still be visible today. However proving the theory would be a far more difficult and time consuming exercise.
National Science Foundation (NSF) program director Peter Kurczynski, who oversaw funding for EDGES, explained how difficult the task would be.
He said, “There is a great technical challenge to making this detection.” published in the journal Nature Peter Kurczynski continued; “Sources of noise can be 10,000 times brighter than the signal – it’s like being in the middle of a hurricane and trying to hear the flap of a hummingbird’s wings.”
Scientists conducting the experiment were certain that the findings could be proven, thanks to previous research suggesting that the first stars in our galaxy during formation released enormous volumes of UV light, radiation that EDGES could detect.
They were correct, but the uncovered signal left scientists astounded, as it was twice as strong as theoretically predicted, this in turn has forced scientists to reassess their findings, and has also given them grounds for further investigation. Scientists and astronomers now faced an even greater query, what caused the findings to be double the amount previously expected?
Although at an early stage yet, astronomers anticipate that the double dip in radiation could have been caused by a reaction with the universe’s most mysterious substance Dark Matter.
Amounting to 85% per cent of the total mass of the universe, very little is known about Dark Matter, and although strongly suggested, it’s existence as of yet, is still to be proven.
Judd Bowman, one of the main astronomers at the Western Australian site. Known as Murchison Radio Astronomy Conservatory (MRO) said of the possible link to Dark Matter. “This is the first time we’ve seen any signal from this early in the Universe.” Speaking to Space.com he continued “If it’s confirmed then we’ve learned something new and fundamental about the mysterious dark matter that makes up 85% per cent of the matter in the universe.
“This would provide the first glimpse of physics beyond the standard model”, Bowman concluded.
Considering that the antennae used is very similar to the FM antennae used on a household radio (another reason the apparatus had to be far removed, from any FM radio signal interference), astronomers were not only able to view the birth and death of the first stars to exist in our universe, but the findings could also lead to greater understanding of Dark Matter, how it interacts with other matter and finally its importance in the creation of the universe itself.