Euclid Space Telescope Discovers 31 New Ancient Quasars

• The ESA's Euclid telescope has identified 31 new high-redshift quasars (6.6 < z < 7.8) within its first 1.5 years of operation.
• Two of these discoveries, at z=7.7 and z=7.69, are now the most distant quasars ever recorded, dating back to 670 million years after the Big Bang.
• This discovery more than doubles the number of known quasars at z ≥ 7, providing a representative sample rather than relying on isolated outliers.

Scientific Significance

• Quasars are active galactic nuclei powered by supermassive black holes; they serve as critical probes for understanding dark matter structures in the early Universe.
• Larger samples allow researchers to test the Lambda-CDM cosmological model more accurately.
• The findings help characterize the Epoch of Reionization, the period when the first stars and galaxies ionized hydrogen in the intergalactic medium.

Methodology

• The data was sourced from approximately 3,000 square degrees of the Euclid Wide Survey.
• Discovery involved advanced machine-learning and probabilistic techniques to distinguish faint quasar signals from foreground Milky Way stars.
• Follow-up spectroscopic verification was conducted using the Keck, Magellan, and Large Binocular Telescope (LBT) observatories.

Future Implications

• The study, led by Daming Yang of Leiden University, provides a foundation for future investigations into the rapid growth of supermassive black holes in the infant Universe.
• Euclid is expected to significantly increase this catalog throughout its six-year mission, offering a "census" of ancient quasars.