University of Michigan researchers were part of an international team that used the European Space Agency’s Euclid space telescope to discover 31 of the most ancient quasars ever observed.
They are so old, in fact, that they date back to the universe’s so-called reionization era, when stars, galaxies and supermassive black holes were first forming.
“This is truly exciting,” said Jinyi Yang, co-author of the new study published in the journal Astronomy & Astrophysics and assistant professor in the U-M Department of Astronomy. “These luminous quasars, shining from deep within the reionization era, the last major transition in our universe’s history, offer invaluable insights into how the cosmos emerged from darkness and how the earliest supermassive black holes formed.”
Quasars are among the brightest, most energetic objects in the universe and are powered by supermassive black holes devouring matter at the center of galaxies. They are short-lived compared to a galaxy’s lifetime, but in that relatively brief moment, quasars can outshine the rest of their host galaxies by hundreds to thousands of times.
By finding the most distant quasars, astronomers can learn more about the early universe. But ancient quasars are rare because few galaxies had enough time to grow large enough to host one. These quasars are also hard to find because their primordial light is both faint and easy to confuse with stars.
But Euclid, which began its cosmological survey in February 2024, is ushering in a new era in that search, said study co-author Feige Wang, U-M assistant research scientist in astronomy.
“The Euclid mission is completely changing the game,” Wang said. “Of those 31 quasars, 12 are above redshift 7, more than doubling all the known quasars that are beyond redshift 7.”
To learn more, please check out this UM press release. Also, please check out this press release from Euclid Consortium for more information.
