For seven years, a team of astronomers searched for rare galaxies in the early universe to estimate their age. They finally succeeded. Data was collected using the James Webb Space Telescope. Astronomers have confirmed the existence of supermassive galaxy JWST-7329 in the early universe, 1.75 billion years old (redshift z = 3.205). Surprisingly, most of its stars are relatively old, ranging in age from 1 billion to 1.5 billion years. In other words, it was born 400 million years after the Big Bang (z = 11). According to the accepted cosmological model, at that time dark matter did not yet have time to accumulate in the large spherical halos in which it is concentrated today. This means that, in theory, it could not have triggered massive star formation just 400 million years after the Big Bang. The approximate total mass of JWST-7329’s stars is 124 billion solar masses. For comparison, the stars in the Milky Way galaxy have half that mass, about 60 billion solar masses. According to standard cosmological models, such galaxies may have formed in the recent past through the merger of many smaller galaxy clusters. The problem is that, according to the model, the stars must still be quite young because their formation is accompanied by an increase in the density of cold dark matter. The authors of the new paper, published in the journal Nature, began their search for galaxy JWST-7329 after analyzing data from infrared observations that began in 2010. The researchers say they used the ground-based Keck Observatory and VLT Observatory to observe the planet for a long time, but the accuracy of their measurements was not sufficient. Object JWST-7329 was too red and too dark. The James Webb Telescope could see it.
A galaxy with stars that are too old has been discovered in a young universe For seven years, a team of astronomers searched for rare galaxies in the early universe to estimate their age. They finally succeeded. Data was collected using the James Webb Space Telescope. Astronomers have confirmed the existence of supermassive galaxy JWST-7329 in the early universe, 1.75 billion years old (redshift z = 3.205). Surprisingly, most of its stars are relatively old, ranging in age from 1 billion to 1.5 billion years. In other words, it was born 400 million years after the Big Bang (z = 11). According to the accepted cosmological model, at that time dark matter did not yet have time to accumulate in the large spherical halos in which it is concentrated today. This means that, in theory, it could not have triggered massive star formation just 400 million years after the Big Bang. The approximate total mass of JWST-7329’s stars is 124 billion solar masses. For comparison, the stars in the Milky Way galaxy have half that mass, about 60 billion solar masses. According to standard cosmological models, such galaxies may have formed in the recent past through the merger of many smaller galaxy clusters. The problem is that, according to the model, the stars must still be quite young because their formation is accompanied by an increase in the density of cold dark matter. The authors of the new paper, published in the journal Nature, began their search for galaxy JWST-7329 after analyzing data from infrared observations that began in 2010. The researchers say they used the ground-based Keck Observatory and VLT Observatory to observe the planet for a long time, but the accuracy of their measurements was not sufficient. Object JWST-7329 was too red and too dark. The James Webb Telescope could see it.