APOD
Astronomy Picture of the Day
Discover the cosmos! Each day a different image or photograph of our fascinating universe is featured, along with a brief explanation written by a professional astronomer.
A Quasar Portrait Gallery
Explanation: Quasars (QUASi-stellAR objects) lie near the edge of the observable Universe . Discovered in 1963, astronomers were astounded that such objects could be visible across billions of light-years, as this implies they must emit prodigious amounts of energy. Where does the energy come from? Many believe the quasar's central engine is a giant black hole fueled by tremendous amounts of infalling gas, dust, and stars. This gallery of quasar portraits from the Hubble Space Telescope offers a look at their local neighborhoods: the quasars themselves appear as the bright star-like objects with diffraction spikes . The images in the center and right hand columns reveal quasars associated with disrupted colliding and merging galaxies which should provide plenty of debris to feed a hungry black hole .
| Date | March 9, 2002 |
|---|---|
| Credit | Credit J. Bahcall ( IAS, Princeton ), M. Disney ( Univ. Wales ), NASA |
| Authors & editors: | Robert Nemiroff (MTU) & Jerry Bonnell (UMCP) |
| A service of: |
ASD at NASA / GSFC, NASA Science Activation & Michigan Tech. U. |



