The James Webb Space Telescope has discovered the oldest pair of supermassive black hole-powered quasars ever observed. Designated J1602+4228AB and nicknamed Nāpōwawāʻenakaulua, the pair appears as it existed 900 million years after the Big Bang.
The two black holes, with masses of 1.5 billion and 400 million times the sun's mass, sit only 18,100 light-years apart. This makes Nāpōwawāʻenakaulua the most compact quasar pair found during Cosmic Dawn, the period shortly after the first stars, galaxies, and black holes formed.
The discovery presents a puzzle for current black hole formation models. According to existing theory, black holes should require at least 1 billion years to feed and merge enough to reach such enormous masses. Yet the JWST has routinely discovered supermassive black holes powering quasars as early as 400 million years after the Big Bang. The existence of Nāpōwawāʻenakaulua, the third quasar pair at Cosmic Dawn, could challenge these models further.
"There is no definitive theoretical explanation for how a single one of these giant quasars exists so early in the age of our universe, much less two," said Silvia Onorato, research team leader at NOIRLab. "We observed Nāpōwawāʻenakaulua at a time when the universe was only a thirteenth of its age and, astonishingly, its supermassive black holes are just as massive as those we see today."
The pair was identified in data from the JWST's Aether survey, which has uncovered 200 quasars just under half of all currently known early universe quasars. Confirmation came from the Gemini North telescope on Maunakea in Hawai'i. The team's results were published November 10 in The Astrophysical Journal Letters.
Onorato noted that Nāpōwawāʻenakaulua serves as "a laboratory for astronomers to study how the very first massive galaxies and their central black holes assembled together through direct galaxy interactions during these early times."