Ancient quasars add to a ‘major unsolved problem’ in astrophysics

A quasar — among the universe’s most luminous and energetic objects — is a supermassive black hole caught in the act of guzzling matter at the ​heart of a galaxy. Scientists have now found quasars dating to so early in cosmic history that they are baffled as to how they already existed ‌at that primordial […]