Quasars, short for quasi-stellar objects, were first identified in 1962 by Maarten Schmidt at the California Institute of Technology. They appear as star-like points, but they lie at enormous distances, which means they’re emitting incredible amounts of energy.
By the 1980s, quasars’ prodigious X-ray and radio emissions led most astronomers to believe these objects contain black holes in their centers. And by the 1990s, scientists increasingly viewed quasars as young galactic cores where gas, dust, and stars fed a central black hole.
One byproduct of the infalling matter is a high-energy jet erupting from near the black hole and hurling material into space. Quasars became part of a spectrum of energetic galaxies called active galactic nuclei (AGN), which also includes Seyfert galaxies, BL Lacertae objects, and radio galaxies. Perhaps these diverse objects, astronomers thought, were similar creatures viewed from different angles.
Slowly, the question of what quasars are morphed into how quasars formed. Observational clues from the Hubble Space Telescope and other instruments able to observe the far reaches of the cosmos are giving astronomers leads. Some quasars seen at high resolution exhibit a “fuzz” of light. In recent years, Hubble has revealed faint galactic forms around quasars. This confirms these distant beacons are, indeed, young galactic cores.
In this episode of Infinity & Beyond, join host Abigail Bollenbach as she provides a quasi-brief rundown of these quasi-stellar objects.