Narrator (April Jubett, CXC): Winter often brings many intense and powerful storms, with cold fronts sweeping across many parts of the globe. There are, however, even bigger weather systems. For example, astronomers have discovered cold fronts in space that are millions of light years in extent and older than the Solar System.
For example, researchers used NASA's Chandra X-ray Observatory to study a cold front located in the Perseus galaxy cluster that extends for about two million light years, or about 10 billion billion miles.
Galaxy clusters are the largest and most massive objects in the Universe that are held together by gravity. In between the hundreds or even thousands of galaxies in a cluster, there are vast reservoirs of super-heated gas that glow brightly in X-ray light.
The cold front in the Perseus cluster consists of a relatively dense band of gas with a "cool" temperature of about 30 million degrees moving through lower density hot gas of about 80 million degrees. The enormous cold front formed about 5 billion years ago and has been traveling at speeds of about 300,000 miles per hour ever since.
The cold front has not only survived for over a third of the age of the Universe, but it has also remained surprisingly sharp and split into two different pieces.
Astronomers expected that such an old cold front would have been blurred out or eroded over time because it has traveled for billions of years through a harsh environment of sound waves and turbulence caused by outbursts from the huge black hole at the center of Perseus. Instead, the sharpness of the Perseus cold front suggests that the structure has been preserved by magnetic fields that are wrapped around it.
Perseus is the same cluster where astronomers use Chandra to discover sound waves with a note of B-flat 57 octaves below middle-C plus a giant wave about twice the width of the Milky Way galaxy. Astronomers will continue to use Chandra and other telescopes to study this fascinating galaxy cluster.
Revised: May 19, 2022