Astronomers have discovered a new space object - the most distant known object to date - a mysterious and strange ancient galaxy 13.5 billion light years away. The galaxy, named HD1, may be home to a cluster of stars that scientists have never seen before, or it may be hiding a black hole with a mass far greater than it should be, based on its age.
Galaxies HD1 and a slightly closer galaxy HD2 have been observed with Spitzer, Subaru, VISTA and the UK Infrared telescope, with the final confirmation coming from the ALMA. Also with the ALMA telescope distance to the HD1 galaxy has been measured with high accuracy, making it the new most distant known space object, pushing down from this pedestal the GN-z11 galaxy, which is about 100 million light years closer to us. For reference, the most distant known single star Earendel, discovered most recently, is 12.9 billion light years away.
Looking into the distant depths of outer space is known to be equivalent to looking into the past of our universe. And we can now see the HD1 galaxy as it was at a time some 300 million years after the Big Bang. Thanks to this, the study of galaxies HD1 and HD2 will give scientists a wealth of new information about the early Universe, and the first observations have already 'revealed' some oddities.
As it turns out, the HD1 galaxy is extremely bright in the ultraviolet, which indicates the existence of very high-energy processes going on in its interior. Astronomers already have two hypotheses about what is happening in that region of space and time.
The first hypothesis states that the HD1 galaxy is experiencing very intense star formation. However, even this would not explain the strength of the ultraviolet light flux emitted by the galaxy, but it could be if the new stars belong to the hypothetical (still) third generation (Population III) of stars. And if this hypothesis proves to be correct, this would be the first time in history that ancient stars of this type have been discovered.
The second hypothesis is the possibility of a supermassive black hole in the centre of the HD1 galaxy with a mass exceeding the mass of the Sun by at least 100 million times. A quasar formed around a black hole intensely absorbing matter from the surrounding space could be the source of such a powerful beam of ultraviolet light. If this, the second hypothesis, is confirmed, this case will be the discovery of the oldest supermassive black hole. And it will raise a number of questions as to how such a monster could have gained mass in the relatively short time of its existence.
Further research on the galaxy HD1 scientists plan to continue using the recently launched James Webb Space Telescope. The infrared telescope is designed to probe the depths of space, reaching farther back in time, and is well suited to the task.
