Active Galactic Nuclei

http://hubblesite.org/newscenter/archive/releases/2000/2000/37/image/a/

Dust in the Heart of Circinus

Infrared observations of the Circinus Galaxy may help reveal the shape of the dusty region fueling its active galactic nucleus and shed light on what governs dust structures in other galaxies.

Quasar illustration

The Quasar Main Sequence

A new diagram might link the diverse visible-light characteristics of quasars to two physical properties — essentially, their accretion rate and orientation. If the analysis holds up, it could point the way toward a long-sought unification.