Arp 220: Spirals in Collision
Explanation:
Arp 220 is the
brightest object in the local universe. But why does it shine so brightly?
Arp 220
was cataloged as a peculiar galaxy in the 1960s. In the late 1980s, it was discovered
to be an
ultraluminous
infrared galaxy and headed a list compiled from observations with the now-defunct
IRAS satellite.
New observations with
the
Hubble Space Telescope are quite revealing.
Photos by
NICMOS
in the
infrared taken in April and released just
last week now better resolve the two colliding
spiral galaxies at the center of
Arp 220.
A result of this
spiral collision are fantastic knots of new star formation
visible as the bright spots on the above photograph. Below the "half-moon" shaped
knot on the right is a massive disk of dust possibly hiding a dying spiral's
central black hole. The bright knot to the left is the
center of the other broken spiral galaxy. The galaxy cores are about 1200 light
years apart and are orbiting each other.
Authors & editors:
Robert Nemiroff
(MTU) &
Jerry Bonnell
(USRA)
NASA Web Site Statements, Warnings,
and Disclaimers
NASA Official: Jay Norris.
Specific
rights apply.
A service of:
LHEA at
NASA /
GSFC
& Michigan Tech. U.
