Galaxies

An Active Galactic Nucleus is a compact, extraordinarily luminous central region of a galaxy powered by accretion onto a...

Blazars are AGN with relativistic jets pointed directly at Earth, producing extreme luminosity, rapid variability, and s...

The cosmic web is the large-scale structure of the Universe, consisting of filaments of galaxies surrounding vast empty ...

Galaxy clusters are the largest gravitationally bound structures in the Universe, containing hundreds to thousands of ga...

Quasars (quasi-stellar radio sources, though most aren't radio-loud) are the most luminous persistent objects in the Uni...

Seyfert galaxies are spiral galaxies with bright, compact nuclei showing strong emission lines, a nearby moderate-lumino...

Starburst galaxies undergo exceptionally intense star formation at rates 100-1,000× higher than normal galaxies, consumi...

Superclusters are massive structures containing multiple galaxy clusters and groups, spanning hundreds of millions of li...