Astronomers discover the 1st-ever merging galaxy cores at cosmic dawn

Astronomers have spotted two active black holes merging at their farthest distance ever — just 900 million years after the Big Bang.

This is the first time that two luminous supermassive black holes have been spotted during cosmic dawn.

Cosmic dawn is the time encompassing the first billion years of the universe. During this period, roughly 400 million years after the Big Bang, the Epoch of Reionization began, in which light from nascent stars stripped hydrogen of their electrons, leading to a fundamental reshaping of galaxy structures.

"The existence of merging quasars in the Epoch of Reionization has been anticipated for a long time." study lead author Yoshiki Matsuoka, an astronomer at Ehime University in Japan, said in a statement. “It has now been confirmed for the first time.”

The researchers published their findings April 5 in the The Astrophysical Journal Letters.

Black holes are born from the collapse of giant stars and grow by ceaselessly gorging on gas, dust, stars and other other black holes in the star-forming galaxies that contain them. If they grow large enough, friction causes the material spiraling into the black holes' maws to heat up, and they transform into quasars — shedding their gaseous cocoons with blasts of light up to a trillion times more luminous than the brightest stars.

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