To find out when the stars in MACS1149-JD1 started shining, Hashimoto's team used infrared data from the Hubble Space Telescope and NASA's Spitzer Space Telescope to determine the observed brightness of the galaxy was well explained by a model in which the onset of star formation was well underway just 250 million years after the Big Bang.
By detecting the most distant oxygen ever found, astronomers have shown that the first stars formed unexpectedly early. According to Takuya Hashimoto, representing the Japanese University of Osaka, this invention allows to significantly extend the boundary of the Universe studied by scientists.
Using the giant ALMA telescope in Chile, researchers were able to observe the distant galaxy MACS1149-JD1 when it was just 550 million years old, a time when it contained stars that were about 300 million years old, the study published on Wednesday said. However, numerous heavier elements we take for granted today (such as carbon and oxygen) did not exist before the first stars. Due to the expansion of the Universe the wavelength is initially infrared radiation during its travel in space has increased more than ten times.
The group derived that the signal was produced 13.3 billion years ago (or 500 million years after the Big Bang), making it the most distant oxygen at any point distinguished by any telescope .
Nicolas Laporte, a researcher at University College London (UCL) in the United Kingdom said, "This galaxy is seen at a time when the Universe was only 500 million years old and yet it already has a population of mature stars".
So now the latest such discovery was made by a team of astronomers using the Atacama Large Millimeter/submillimeter Array and European Southern Observatory's Very Large Telescope when observing the very distant galaxy MACS1149-JD1. "This detection pushes back the frontiers of the observable Universe". They measured the frequency of a peak in the galaxy's spectrum that comes from ionized oxygen gas.
If astronomers discovered oxygen in MACS1149-JD1, it meant that inside the galaxy, stars have formed even earlier and died in the galaxy.
One of the most burning questions on astronomers" minds is: "When did the first galaxies emerge from total darkness?
Co-author Professor Richard Ellis, also from UCL, said: "Determining when cosmic dawn occurred is akin to the Holy Grail of cosmology and galaxy formation". That gives us an indication of how much earlier in the history of the Universe - which we can't now probe with our telescopes - that this object actually formed. There is renewed optimism we are getting closer and closer to witnessing directly the birth of starlight. "Since we are all made of a processed stellar material, this is really finding our own origins".