Scientists have noticed the most distant galaxy in history

The HD1, a red object, appears in the center of the magnified image. Author: Harikane et al.

An international team of astronomers, including researchers from the Center for Astrophysics Harvard & Smithsonian noticed the most distant astronomical object ever: the galaxy.

The galaxy candidate, named HD1, is about 13.5 billion light-years away and was described Thursday in Astrophysical Journal. In an accompanying article published in Art Monthly notifications of letters from the Royal Astronomical Societyscientists have begun to believe what exactly is a galaxy.

The team offers two ideas: HD1 can form stars at amazing speeds and may even be home to the stars of Population III, the very first stars in the universe that have never been observed before. In addition, HD1 may contain a supermassive black hole that weighs about 100 million times the mass of our Sun.

“Answers to questions about the nature of a source that is so far away can be challenging,” says Fabio Pacucci, lead author. MNRAS research, co-author of the opening paper on ApJ, and an astronomer at the Center for Astrophysics. “It’s like guessing the ship’s nationality by the flag it hovers far offshore, and the ship is in squalls and thick fog. You may be able to see some colors and shapes of the flag, but not completely.” Ultimately, it’s a long game of analyzing and eliminating incredible scenarios. ”

The HD1 is extremely bright in ultraviolet light. To explain this, “some energy processes take place there or, better yet, took place billions of years ago,” Pakuchi says.

At first, researchers believed that HD1 was a standard star burst galaxy, a galaxy that creates stars at high speed. But after counting how many stars HD1 produces, they got “incredible speed – HD1 will form more than 100 stars each year. That’s at least 10 times higher than we expect for these galaxies. “

It was then that the team began to suspect that HD1 might not form the usual everyday stars.

“The very first population of stars that formed in the universe was more massive, brighter and hotter than modern stars,” says Pakuchi. “If we assume that the stars obtained in HD1 are the first, or the stars of Population III, then their properties could be explained more easily. In fact, the stars of Population III are able to produce more UV light than ordinary stars. that can clarify the extreme ultraviolet luminosity of HD1 ”.

Scientists have noticed the most distant galaxy in history

The timeline shows the earliest candidates for galaxies and the history of the universe. Author: Harikane et al., NASA, EST and P. Oesch / Yale.

The supermassive black hole, however, could also explain the extraordinary luminosity of the HD1. Because it absorbs huge amounts of gas, high-energy photons can be emitted by the area around a black hole.

If so, it will be the earliest supermassive black hole known to mankind, observed much closer in time to the Big Bang compared to the current record holder.

“HD1 will represent a giant baby in the delivery room of the early universe,” said Avi Loeb, an astronomer at the Center for Astrophysics and co-author. MNRAS study. “It breaks the highest redshift quasar in history nearly twice, it’s a remarkable feat.”

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

“It was very difficult to find HD1 with more than 700,000 objects,” said Yuichi Harikane, an astronomer at the University of Tokyo who discovered the galaxy. “The red color of the HD1 was surprisingly well-matched to the expected characteristics of a galaxy 13.5 billion light-years away, which caused me a little goosebumps when I found it.”

The team then conducted the following observations using the large millimeter / submillimeter array Atacama (ALMA) to confirm a distance that is 100 million light-years farther than GN-z11, the current record holder of the most distant galaxy.

Using the James Webb Space Telescope, the research team will soon be observing HD1 again to test its distance from Earth. If current calculations turn out to be correct, HD1 will become the farthest and most ancient galaxy ever recorded.

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

“Formed a few hundred million years after the Big Bang, the black hole in HD1 was supposed to grow from a massive seed at an unprecedented rate,” Loeb says. “Again, nature looks more imaginative than we do.”

Astronomers confront a massive black hole in the center of the Milky Way, Sagittarius A *

Additional information:
Search for Lyman-H-Dropout galaxies at z ~ 12-16, arXiv: 2112.09141 [astro-ph.GA], Accepted for publication in Letters from MNRAS.

Are the recently discovered sources of z∼13 falling galaxies or quasars ?, arXiv: 2201.00823 [astro-ph.GA], Accepted for publication in ApJ.

Provided by the Harvard-Smithsonian Center for Astrophysics

Citation: Scientists have discovered the most distant galaxy in history (2022, April 7), obtained on April 7, 2022 from

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