The HST image shows clearly that the quasar, called 1229+204, lies in the core of a galaxy that has a common shape consisting of two spiral arms of stars connected by a bar-like feature. The host galaxy is in a spectacular collision with a dwarf galaxy. The collision apparently fuels the quasar "engine" at the galaxy center - presumably a massive black hole -- and also triggers many sites of new star-formation.
The image is one of a pair of relatively
nearby quasars that were
selected as early targets to test the resolution and dynamic
range of HST's newly-installed Wide Field and Planetary Camera,
which contains special optics to correct for a flaw in Hubble's
primary mirror. The observations were made by Dr. John Hutchings
of Dominion Astrophysical Observatory in Victoria, British
Columbia. "The project was impossible from ground-based
telescopes," says Dr. Hutchings, who has been researching quasars
for many years. " The sharpness of the Hubble pictures is leading
to major new discoveries almost anywhere you point it in the
sky."
Though a previous ground based observation using the Canada-France-Hawaii Telescope (at 0.5 arcsec resolution) first identified the barred spiral galaxy in 1229+204, Hubble shows clearly the galaxy's structure and reveals details of the collision.
Hubble reveals that an extended blue feature on one side of the
galaxy is really a string of knots, which are probably massive
young star clusters. The star clusters were most likely formed
as a result of a collision between the host galaxy and a small
gas-rich companion. HST also reveals shell-like structures
along the bar that might be produced by gravitational tidal
resonance forces between the spiral and its companion.