Astronomers using the Euclid space telescope have identified 31 of the oldest known quasars, including the two earliest ever detected. These objects date to when the universe was only about 670 million years old.
The findings, published in Astronomy & Astrophysics, include 14 quasars with redshifts of 7 or greater. The two oldest have redshifts of 7.69 and 7.77, surpassing previous records.
Co-author Joseph Hennawi of UC Santa Barbara and Leiden University noted that these supermassive black holes, weighing billions of times the Sun's mass, already existed when the universe was in its infancy. Lead author Daming Yang, a doctoral student at Leiden University, highlighted the challenges of detecting such distant objects amid stars in the Milky Way.
The European Space Agency's Euclid telescope, launched in 2023, enabled the discoveries through its wide and deep survey above Earth's atmosphere. Researchers confirmed many of the quasars using the Keck telescopes and plan further studies with the James Webb Space Telescope and the Atacama Large Millimeter Array.
The team aims to find the first quasar beyond a redshift of 8, which would date to within the universe's first 630 million years.