NGC 4697: X Rays from an Elliptical Galaxy
Explanation:
The many bright, point-like sources in
this
Chandra Observatory x-ray image lie within NGC 4697, an
elliptical galaxy some 40 million
light-years away towards
Virgo.
Like other normal
elliptical
galaxies, NGC 4697 is a spherical
ensemble of mainly older, fainter, low mass stars, with
little star forming gas and dust compared to spiral galaxies.
But the luminous
x-ray
sources in the Chandra image indicate that
NGC 4697 had a
wilder youth.
Powering the
x-ray sources are neutron stars
and black holes in
binary
star systems, where x-rays are generated as matter from
a more ordinary companion star falls in to these bizarre,
compact objects.
Since
neutron
stars and
black holes
are the endpoints in the lives of
massive stars, NGC 4697 must have had many bright, massive stars
in its past.
An exceptionally large number of NGC 4697's x-ray binaries are
found in the galaxy's globular star clusters, suggesting that
dense star clusters
are a good place for
neutron stars and
black holes to capture a companion.
Stellar winds and
supernovae explosions of massive stars
could also have produced the hot gas responsible
for this galaxy's diffuse x-ray glow.
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.
