The discovery of the oldest quasar ever found by ESA's Euclid Telescope is a groundbreaking achievement, pushing the boundaries of our understanding of the universe. This remarkable find, along with 30 other quasars, offers a glimpse into the early universe, just a billion years after the Big Bang. What makes this discovery even more fascinating is the speed at which it was made. Euclid, designed for a different purpose, identified these ancient objects in just 18 months of operations, covering a fraction of its planned survey area.
One of the most intriguing aspects of this discovery is the quasar's extreme brightness. With the luminosity of one trillion suns, it outshines every star in its galaxy. This brightness allowed Euclid to spot the object despite its enormous distance. The quasar's light began traveling towards Earth when the universe was only about 670 million years old, or roughly five percent of its current age. This makes it the most distant quasar ever discovered, with a measured redshift of 7.77.
The quasar, EUCL J172902.75+641018.1, existed in a very different universe than the one we know today. Most galaxies were still young, many had only recently begun forming stars, and the large-scale structure of the universe was still evolving. This period, known as the epoch of reionization, laid the foundations for everything we see in the modern universe.
The discovery of these ancient quasars raises a deeper question: how did the first supermassive black holes appear so quickly? The answer to this question may lie in the rapid growth of young galaxies, fueled by fresh supplies of gas and intense bursts of star formation. The study of these quasars and their host galaxies can provide valuable insights into the early universe and the formation of supermassive black holes.
Euclid's infrared vision and wide field of view were crucial in capturing the ancient light of these quasars. Its ability to observe in near-infrared wavelengths allowed it to detect the stretched light from the earliest galaxies and quasars, which are almost invisible to ordinary optical telescopes. The telescope's wide field of view also enabled it to scan huge areas of the sky, covering about 3,000 square degrees in just 18 months.
In my opinion, the discovery of these ancient quasars is a significant milestone in astronomy. It not only pushes the boundaries of our understanding of the universe but also raises new questions and challenges for future research. The study of these objects will require advanced techniques and technologies, and it will be fascinating to see how astronomers continue to explore the early universe and its secrets.
