A new image shows evidence for a galaxy being stripped bare of its star-forming
material by its violent ongoing encounter with the hot gas in the center of
a galaxy cluster, astronomers announced last week.
The picture, from the WIYN 3.5-meter telescope on Kitt Peak, was presented
last week at a meeting of the American Astronomical Society.
The disruptive process is believed to influence the evolution of galaxies and
their star-forming ability over time, but direct observational evidence has
been somewhat scant.
The galaxy, NGC 4402, is more than 50 million light-years from Earth. It is
in the midst of the relatively nearby Virgo cluster of galaxies. As the NGC
4402 moves toward the center of the cluster (located out of the image toward
the bottom left), it experiences a "wind" from hot gas that permeates
the cluster and which reaches temperatures of millions of degrees.
"This hot wind strips out the much cooler gas and dust in the galaxy,"
Hugh Crowl of Yale University. "This is important because the gas is raw material
for new stars, and once this gas is stripped, the galaxy can no longer form
new stars and becomes ‘dead’ in a sense."
Crowl said there are four lines of evidence:
