Observations carried out by a powerful radio telescope have detected the presence of a galactic disk that can assist in understanding the origin of the Universe. Composed of a massive amount of gas, it is found in a system formed about 1.5 billion years after the big bang – presenting us, earthlings, with a real time travel.
Dark matter, gas, dust, stars and massive celestial bodies … All of this is part of the composition of galaxies and, if you want to find out more information about where we came from, try to understand how these systems emerged and grew, creating structures of proportions unimaginable, is part of any scientific study dedicated to the area. Galactic discs are key parts of this investigation, as their first appearances date back to billions of years of history; therefore, understanding them can help reveal several issues.
Galactic disk captured by Hubble exemplifies the phenomenon. ESA
The most striking fact is that the stipulated date of his birth is considerably more distant than that of the oldest seen so far. According to current cosmological knowledge, the first large-scale universal structures were spherical halos of dark matter, which, due to their immense gravity, collapsed and left surrounding gases (the discs).
Everything that fell in the halos gave rise to the stars and, consequently, to the galaxies. After that, it is assumed that systems have continued to grow with a given hierarchy of matter – some have actually expanded; others have become extinct.
Therefore, a heated debate in the scientific community is recurrent: how exactly did the accumulation of matter necessary for these systems to arise, given the variation in formats? For example, in more recent galaxies, like ours, disks of dust and gas are observed, something that does not happen in older ones.
Apparently, this hierarchy that occurred in remote times is the key to new clarifications – since it can destroy or promote the growth of the disc.
There are two modes of accumulation of gases: hot and cold. In hot weather, increased gases take longer to lose heat and form other matter when they fall into the dark matter in the halo, which results in late galaxies. In the cold, the process occurs much faster, and the oldest galaxies are without the brightness of the disks.
To visualize these structures, highly sensitive instruments are needed. The further they are, the more “we go back in time”, since the light that arrives here was emitted many, many years ago. High-resolution data showed that certain discs discovered appeared about 3 billion years after the big bang. The technology, of course, advances more and more, allowing researchers to discover the approximately 1.5 billion years older specimen detailed in the journal Nature.
To achieve this, a team of scientists used the Atacama Large Millimeter Array, a radio observatory built in Chile. From there, they visualized signs of a galaxy formed about 12.5 billion years ago. With the details, models were structured, and the results indicated information in line with that found through other galactic discs.
ALMA, structure used for observations. Reddit
The revelation was surprising, considering the proximity of the birth of the structure to the appearance of the Universe. Even though it is just one copy, this is enough for the projections made so far to be reformulated and bring new questions based on small answers about the beginning of everything.