Map shows how patterns align, suggesting way to keep spiral arms stable
R. Beck/MPIfR, NRAO/AUI/NSF; U. Klein/AIfA (graphics); T.A. Rector/University of Alaska
New maps of the nearby galaxy IC 342 show that its magnetic fields closely mimic its spiral arms of gas and stars. The similar pattern suggests that galactic magnetic fields have some role to play in molding spiral galaxies, astronomer Rainer Beck reports June 11 in Astronomy & Astrophysics.
“The magnetic field can help stabilize the spiral pattern,” says Beck, of the Max Planck Institute for Radio Astronomy in Bonn, Germany.
Spiral arms are a bit puzzling. As a galaxy’s disk of gas spins, hiccups in the gas can set up spiraling waves. The waves compress the gas, which gravitationally collapses to form stars, lighting up the spiral arms. But simulations suggest that the spiral pattern should fall apart relatively quickly.
Magnetic fields aligned across tens of thousands of light-years might act as glue for ionized gas, says Beck. The rotating galaxy