Astronomers have just detected a galaxy 13.5 billion light years away, it would be the farthest to date – Teach Me About Science

It seems that the record for the most distant galaxy has been set. The red object in the center of the enlarged image is the candidate, HD1. (Credit: Harikane et al).

There is no doubt that we are living in an exciting time. A few days ago we received the news that Hubble had made an unprecedented discovery: it was nothing more and nothing less than the most distant individual star ever observed. The discovery marked an important milestone since it is like jumping back in time to study the early universe.

Now, astronomers say that we may be facing a new impressive discovery, as it seems that a galaxy has been detected whose light has traveled a whopping 13.5 billion light years. That would be historic, if confirmed it would become the most distant galaxy that has been detected to date.

The outermost galaxy candidate called HD1 was put forward by an international team of scientists. It is estimated to be 100 million light-years further away than the current farthest galaxy (GN-z11) which is 13.4 billion years away. The universe is 13.8 billion years old, so it’s pretty amazing when you think about it being around 300 million years after the Big Bang.

The candidate for the most distant galaxy and the history of the Universe. (Credit: Harikane et al., NASA, ESA, and P. Oesch Yale University).

Distant objects like HD1 is the goal of the James Webb Space Telescope (JWST), which is currently in the process of aligning and calibrating its instruments. Webb will be in charge of confirming the exact location of this galaxy and then we will know if it is actually the most distant and oldest that has been detected so far.

“We found a weak signal at the frequency where an oxygen emission line was expected. The statistical significance of the signal is 99.99%. If this signal is real, there is evidence that HD1 exists 13.5 billion light-years away, but we can’t be sure without a significance equal to or greater than 99.999%.” Explain Akio Inoue, a professor at Waseda University who led the ALMA observations.

It can be said that this is a new task assigned to Webb, which is the most sophisticated observatory in orbit. It is outside the capabilities of the Hubble Space Telescope that discovered the record-holding galaxy, GN-z11.

According to the ALMA observatorythe new earliest or most distant galaxy candidate, HD1, was discovered from more than 1,200 hours of observational data taken by the Subaru, VISTA, UK Infrared and Spitzer Space Telescopes.

“It was hard work to find HD1 among more than 700,000 objects”, Yuichi Harikane said in a statement, who discovered HD1. “HD1’s red color matched the expected features of a galaxy 13.5 billion light-years away surprisingly well, giving me goosebumps when I found it.”

The galaxy in question is particularly bright, suggesting that very bright objects have existed since the early universe. Because observational information is scarce, there are still doubts about its physical properties. There are some possibilities that can explain its peculiarity, it could be a star-forming galaxy or contain a colossal active supermassive black hole.

Its astronomical importance lies in the fact that it helps us understand the evolution of the universe. We are talking about studying a very old object, when what we now call “everything” was just beginning. Comparing what the ancient galaxies and stars were like with the current ones helps cosmologists to be able to model not only the past, but also the future of the universe.

The discovery appears in the Astrophysical Journal, with an accompanying article in Monthly Notices of the Royal Astronomical Society Letters.

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