Quasars

Distant Light Some objects in deep space are visible, small, and have large redshifts. Very distant by Hubble’s law Billions of light years away larger wavelength nearby galaxy distant object

Quasi-Stellar Objects These objects were first observed as intense radio sources. Bright, but star-sized They were named quasi-stellar radio sources—quasars. Quasars emit in all parts of the electromagnetic spectrum. 100 times Andromeda Brighter flares 3C279, a quasar photographed in gamma rays

Distant Past Looking at a faraway object is like looking back in time. If a quasar is 4 billion ly away, we are seeing the universe 4 billion years ago. Early life of galaxies Andromeda — 2 million years ago Earth PKS 1127 — 4 billion years ago

Disk and Jets Radio measurements show two giant jets of radiating gas. Visible light and x-rays see a disk of gas, dust and stars. Most intense at center

Jet Formation Quasars form from a supermassive black hole. The black hole draws stars and dust to its center. The material is accelerated to high velocity and ejected out either side.

Active Nuclei Some nearby galaxies show jets of radiating gas. Start at galactic black hole Active from dust falling in Quasars fade to active galaxies as dust decreases.

Radio Galaxies Visible elliptical galaxies have black holes in their center. The jets are only seen with radio telescopes. Radio galaxies Active spiral galaxies are called Seyfert galaxies.

Colliding Black Holes The Chandra X-ray Observatory has observed two supermassive black holes in the same galaxy. NGC 6240: 400 Mly When the holes collide in a few hundred million years, the gravity waves will be felt on earth.