Discovery of Dust-Covered Quasars in the Early Universe

Astronomers using the Subaru and James Webb telescopes have discovered seven ultra-bright, dust-covered quasars from a time when the universe was less than a billion years old. This discovery sheds light on a deeper understanding of the formation of giant black holes in the early stages of the universe’s history.

Quasars at the Dawn of the Universe

Quasars are supermassive black holes that consume vast amounts of matter and emit powerful radiation across the electromagnetic spectrum. They are believed to have played a crucial role in the formation of galaxies and the evolution of the universe. However, the formation of these black holes in the early periods of the universe has remained a mystery to scientists.

The dawn of the universe is known as the period from 50 million to a billion years after the Big Bang, during which the first stars and galaxies are thought to have formed. If there were a significant number of black holes at this time, it suggests they formed frequently and on a large scale as a result of the deaths of the first stars.

Techniques Used in the Discovery

Scientists utilized the Subaru Telescope to discover more than 200 quasars, but faced challenges due to cosmic dust that absorbs ultraviolet radiation. Therefore, they turned to the James Webb Telescope to examine these galaxies in infrared light, allowing them to see the obscured quasars.

The team used the HSC-SSP instrument on the Subaru Telescope to search for highly luminous galaxies showing signs of high-energy emissions. They then examined these galaxies with the James Webb Telescope, which studied 11 of them, revealing clear signs of quasars in seven galaxies.

Significance of the Discovery

The findings indicate that obscured quasars may be as common as unobscured ones, suggesting that the number of quasars in the early universe could be twice as high as previously thought. This discovery highlights the importance of using multiple techniques to uncover the hidden secrets of the universe.

The study emphasizes that the dust surrounding quasars absorbs about 99.9% of ultraviolet light and 70% of visible light, explaining the difficulty in detecting these celestial objects.

Conclusion

In conclusion, this discovery marks an important step toward a better understanding of the formation and evolution of supermassive black holes in the universe. Researchers plan to continue studying these obscured quasars to understand their different environments compared to unobscured quasars, and to seek out more of them in galaxies that existed in the early ages of the universe.