A very deep shot of NGC 5792 in Libra. The catalogue positions of some 22 quasars and active galactic nuclei, together with their spectral shift z are shown, using NASA's million quasar catalogue.
The catalogue is patchy, and by luck only covers the bottom half of the image.
Two of the objects circled are relatively close (z around 0.1), and show a resolvable galaxy. Most are at extreme distance, over 8 billion light years. They are intensely blue. The light would have been ultraviolet when emitted. The furthest has a z of 3.5, the light having been emitted about 12 billion years ago.
Aspen CG16M on 20" PlaneWave. Lum 18rhs, RGB 3hrs each, all in 1hr subs.
NGC 5792quasarAGNactive galactic nucleus