By studying quasars we can see chemical elements like oxygen, nitrogen, carbon, and iron, were created as the surrounding galaxy was born. The major result has been the understanding that the light we see from quasars is emitted by many clouds of gas orbiting black holes with masses a billion times greater than the sun. Detailed analysis of the emission reveals that the gas has much more carbon, nitrogen, and oxygen, than is found in our solar system. Massive short-lived stars make these elements. We infer that the quasar phenomenon is the birth of the first generations of massive galaxies in the young universe.
HII regions are places where stars are now being born, in our own galaxy.
I have been investigating the nearest HII region, the Orion Nebula, to probe the current chemical state of the Universe. Nearly all the helium in an HII region was produced during the first 5 minutes of the creation of the universe. Accurate measurements of He then provide a decisive test of the Big Bang. The amount of silicon, iron, calcium, and aluminium tells us about the formation of the solid matter in the interstellar medium. Some think that the first steps to life occurred in this environment.