A quasar is a very bright and distant object in space that emits a lot of energy. It is believed to be powered by a supermassive black hole at its center. Full definition
The mystery deepened with the discovery of quasars in the 1960s. (stsci.edu)
She is primarily an observational astronomer, working on the analysis and interpretation of high - resolution spectroscopy of distant quasars as well as near - infrared and optical spectroscopy of high - redshift galaxies. (carnegiescience.edu)
Ionised clouds could provide this, but had only been glimpsed via the chemical signature they impart on light reaching us from quasars in other galaxies. (newscientist.com)