Astronomers Have Just Identified The Most Distant Galaxy Ever Discovered

A glowing red object in the early Universe has been identified as the most distant.

Astronomers have discovered that a galaxy existed just 330 million years after the Big bang.

Its light had to travel over 13 billion light-years to reach us.

The discoverers have named the object HD1, and it is a mystery. The scientists are not sure what the galaxy is, whether it is a quasar with a massive black hole at its center, or a starburst galaxy with star formation.

If it is the latter, the growth of the black hole to super massive size so soon after the Universe winked into existence presents a challenge to models of black hole formation and evolution.

Answering questions about the nature of a source so far away can be difficult.

It is like guessing the nationality of a ship from the flag it flies while it is in the middle of a gale and dense fog. Some colors and shapes of the flag can be seen, but not in their entirety. It is a long game of analysis and exclusion of implausible scenarios.

It is difficult to detect objects from the early Universe. Our most powerful telescopes are unable to pick up their light because quasars are dim across the vast reaches of space-time.

HD1 was discovered as part of a survey to discover galaxies at the beginning of the Universe, the results of which are detailed in a paper accepted for publication in The Astrophysical Journal, and also available on arXiv.

An analysis of HD1 and HD2 has been accepted into the Monthly Notices of the Royal Astronomical Society and is available on arXiv.

Four powerful telescopes were used in the survey, including the VISTA Telescope, the UK Infrared Telescope, and the Spitzer Space Telescope. They spent over a thousand hours looking into the Cosmic Dawn to find light in the early Universe.

astronomer Yuichi Harikane of the University of Tokyo in Japan says it was very hard to find HD1 out of hundreds of thousands of objects.

HD1's red color matched the expected characteristics of a galaxy 13 billion light-years away, giving me a little bit of goosebumps when I found it.

When a source of light is moving away from us, the red color is called redshift. The wavelength of the light coming from that source increases towards the red end of the spectrum, which is why it's called redshifting.

The Universe is expanding and so other galaxies are redshifted. Calculating how far light has traveled to reach us is possible thanks to this effect.

The light from HD1 is confusing. It is very bright in the ultraviolet wavelength, which suggests that a very energetic process was taking place in the galaxy. The number of stars that would have to be forming to produce that much light was calculated by the researchers.

The number was over 100 stars a year. That is 10 times higher than expected. If the stars being born weren't the same as the stars we see today, the tension could be solved.

The first population of stars that formed in the Universe were more massive, hotter and brighter than modern stars.

If we assume the stars produced in HD1 are Population III, then its properties could be explained more easily. Population III stars are capable of producing more UV light than normal stars, which could clarify the extreme ultraviolet luminosity of HD1.

If the galaxy was a quasar, that's the other option. That is the result of an active galactic nucleus, with a black hole consuming material at such a rapid rate that the heat generated sparks of light across the Universe.

The team calculates that the black hole would have to be 100 million times the mass of the Sun to produce the light.

Black hole growth models are challenged by that size. It is very early in the Universe.

A black hole in HD1 must have grown out of a massive seed at an unprecedented rate, according to an astronomer.

Nature appears to be more imaginative than we are.

The team hopes that future observations with the James Webb Space Telescope will reveal the nature of the dawn light.

The Astrophysical Journal and the Monthly Notices of the Royal Astronomical Society accepted the research. There are papers on arXiv.