3D map of over 1 million black holes traces where the universe's dark matter lies
Nearly 1.3 million quasars are included in a vast cosmic map, with the most distant having existed just 1.5 billion years after the Big Bang.
TroibNews 
Nearly 1.3 million quasars are included in a vast cosmic map, with the most distant having existed just 1.5 billion years after the Big Bang.
