A quasar is an active galactic nucleus, implying that the Nosedeen Quasar resides at the centre of a galaxy. Whether that means the centre of the Milky Way Galaxy, or some other galaxy and the Nosedeenians emigrated to the Milky Way is unclear.
A quasar consists of a supermassive black hole surrounded by an orbiting accretion disk of gas. The core of the quasar is therefore uninhabitable. The Nosedeenians evolved and reside within the high-energy accretion disk of the Nosedeen Quasar.