3C 295: X-rays From A Giant Galaxy
Did this galaxy eat too much?
Five billion light-years away,
the giant elliptical galaxy 3C295
is a prodigious source of
energy at radio wavelengths.
Bright knots of
X-ray emission are also seen at the center of
this false-color Chandra Observatory image of the region.
The X-ray and radio emission are believed to be the result of
an explosive event triggered when too much material flowed
into a supermassive
black hole at the heart of the giant galaxy.
Additionally, the
Chandra
picture beautifully reveals an extensive
cloud of 50 million degree gas surrounding
3C295.
Embedded in the cloud is a
cluster of about 100 galaxies,
too cool to be seen in the X-ray picture.
About two million light-years across, the
X-ray hot cloud
itself contains enough material to create another
1,000 galaxies or so making the cluster and cloud among
the most massive objects in the Universe.
However, X-ray data indicate that there is
still not enough observed mass to hold the cloud and cluster together
gravitationally,
suggesting the presence of large amounts of
dark matter.