The Outer Shells of Centaurus A
Explanation:
What causes the surrounding shells in peculiar galaxy Cen A?
In 2002 a fascinating image of peculiar galaxy
Centaurus A was released,
processed to highlight a
faint blue arc indicating an ongoing collision with a smaller galaxy.
Another interesting feature of
Cen A, however,
is the surrounding system of
shells, better visible here in
this recently released wider pan from the
four meter Blanco telescope at
Cerro Tololo Inter-American Observatory.
Faint shells around galaxies are not unusual
and considered by themselves as evidence of a previous
galaxy merger, analogous to water
ripples on a pond.
An
unexpected attribute of these
shells
is the abundance of gas, which should become separated from existing stars during
the
collision.
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.
