M77: Spiral with a Strange Glow
Explanation:
Why is M77 surrounded by an ultraviolet glow?
M77, also called NGC
1068, appears at first sight to be a relatively normal
barred spiral galaxy. But when photographed in the
ultraviolet (UV), as
shown
above in false color, the galaxy sports an
ultraviolet halo - shown as violet in the photograph.
The blue spiral structure closer to the picture's center indicates normal ultraviolet
emission from bright young stars that have recently formed there.
Astronomers now hypothesize that the outer glow arises from UV light emitted
from the galaxy's active center and reflected to us from clouds of
gas and
dust. These same gas and dust clouds obscure
the active center of this
Seyfert galaxy - where an ultramassive
black hole is thought
to live.
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.
