Scientists have discovered the farthest galaxy ever

An international team of astronomers includes researchers at the Center for Astrophysics | Harvard and Smithsonian, spotted the most distant astronomical object ever: the galaxy.

The candidate galaxy called HD1 is located about 13.5 billion light-years away and was described on Thursday in Astrophysical Journal. In an accompanying paper published in Monthly notifications of letters of the Royal Astronomical SocietyAnd the Scientists are beginning to speculate what exactly a galaxy is.

The team proposes two ideas: HD1 may be forming stars at an astonishing rate, and it may be home to Population III stars, the universe itself. first stars– that hasn’t been noticed yet. Alternatively, HD1 may contain a supermassive black hole with a mass about 100 million times the mass of our sun.

Says Fabio Paccucci, lead author of MNRAS Study, co-author of a discovery paper on a B C, and an astronomer at the Center for Astrophysics. “It is like guessing the nationality of a ship from the flag you are flying, while it is far on shore, and the ship is in the midst of a thick and stormy fog. One can perhaps see some of the colors and shapes of the flag, but not in its entirety. It is ultimately a long game of analysis and exclusion of implausible scenarios. “.

HD1 is extremely bright in UV light. To explain it, “some active process is happening there or, better yet, it happened a few billion years ago,” says Pacuchi.

At first, the researchers hypothesized that HD1 is a galaxy with a standard starburst, a galaxy that is creating stars at a high rate. But after counting how many stars HD1 was producing, they got an “incredible rate — HD1 will be creating more than 100 stars every year. That’s at least ten times higher than what we expect for these galaxies. “

That’s when the team began to suspect that HD1 might not be forming regular, everyday stars.

“The first group of stars that formed in the universe was much more massive, brighter and hotter than modern stars,” says Pacuchi. “If we assume that the stars produced in HD1 are the first, or group III, stars, then their properties can be explained more easily. In fact, the stars of the third group are able to produce more ultraviolet light than normal stars, which may explain the maximum luminosity above Violet for HD1.”

However, a supermassive black hole could also explain the intense luminosity of HD1. When it devours huge amounts of gas, high-energy photons may be emitted from the region around the black hole.

If so, it will be as soon as possible giant black hole Known to mankind, it was observed much closer to the Big Bang than the current record holder.

says Avi Loeb, an astronomer at the Center for Astrophysics and co-author of MNRAS study. “It breaks the highest recorded redshift of the quasar by nearly two times, which is an impressive feat.”

HD1 was discovered after more than 1,200 hours of observation time using the Subaru telescope, the Vesta telescope, the British Infrared Telescope and the Spitzer Space Telescope.

“It was very hard work to find HD1 out of more than 700,000 objects,” says Yuichi Harikan, the astronomer at the University of Tokyo who discovered the galaxy. “HD1’s red color surprisingly matches the expected characteristics of a galaxy 13.5 billion light-years away, which gave me goosebumps when I found it.”

The team then performed follow-up observations using the Atacama Large Millimeter/ Submillimeter Array (ALMA) to confirm the distance, which is 100 million light-years from GN-z11, the current record holder for the farthest galaxy.

Using the James Webb Space Telescope, the research team will soon again monitor HD1 to verify its distance from Earth. If current calculations prove correct, HD1 will be the most distant and oldest galaxy ever recorded.

The same observations will allow the team to dig deeper into HD1’s identity and confirm whether one of their theories is correct.

“Formulated a few hundred million years after the Big Bang, HD1’s black hole must have grown from a massive seed at an unprecedented rate,” says Loeb. “Again, nature seems more creative than us.”