Dusty grains – including tiny specks of the minerals found in the gemstones peridot, sapphires and rubies – can be seen blowing in the winds of a quasar, or active black hole, in this artist’s concept.
Astronomers using NASA’s Spitzer Space Telescope found evidence that such quasar winds might have forged these dusty particles in the very early universe. Dust is crucial for efficient star formation as it allows the giant clouds where stars are born to cool quickly and collapse into new stars. Dust has been seen as far back as when the universe was less than a tenth of its current age, but how did it get there?
Theorists predicted that winds from quasars growing in the centers of distant galaxies might be a source of this dust. While the environment close to a quasar is too hot for large molecules like dust grains to survive, dust has been found in the cooler, outer regions. Using Spitzer’s infrared spectrograph instrument, scientists found a wealth of dust grains in a quasar called PG2112+059 located at the center of a galaxy 8 billion light-years away. The grains – including corundum (sapphires and rubies); forsterite (peridot); and periclase (naturally occurring in marble) – are not typically found in galaxies without quasars, suggesting they might have been freshly formed in the quasar’s winds.Image credit: NASA/JPL-Caltech