Bubbles that burst deep in the heart of the galaxy NGC 1275, seen above, created tentacles of cold gas that have mysteriously lingered in the surrounding heat for up to a hundred million years.
Now a team of international researchers thinks it knows why this cosmic “jellyfish” hasn’t lost its sting.
Andrew Fabian at the U.K.’s University of Cambridge and colleagues analyzed images of the streamers captured by the Hubble Space Telescope and proposed that the galaxy’s large but delicate filaments are held together by magnetic fields.
When the supermassive black hole at the center of NGC 1275 blasts bubbles of cold gases into space, it forms filaments that can be up to 20,000 light-years long and 280 light-years across. Such ribbons should dissipate into the surrounding hot gases, which are about 70 million degrees Fahrenheit (40 million degrees Celsius).
But in a new paper in this week’s issue of the journal Nature, Fabian and colleagues suggest that when the filaments shoot outward, they take some of the galaxy’s magnetic field with them. Although the strength of the filaments’ fields is low—about one ten-thousandth the strength of Earth’s magnetic field—it’s enough to help them hang together.
“The pressure of that magnetic field is comparable to the pressure of the hot gas surrounding it,” Fabian said. The field stops the filaments from collapsing under their own gravity and stops hot gas from evaporating the cold streamers.
Further understanding of how the streamers stay together could provide a model for studying other distant young galaxies, which often appear to be surrounded by such filaments, Fabian added.