Powerful but unknown forces are at work in a small companion galaxy of the Milky Way, astronomers say in todays issue of the journal Science.
Something is keeping the structure and magnetic field of this galaxythe Large Magellanic Cloudstrong and ordered, even while the Milky Ways gravity works to tear them apart.
A team led by Bryan Gaensler of the Harvard-Smithsonian Center for Astrophysics used the CSIRO Australia Telescope near Narrabri in NSW to study the galaxys magnetic field.
This is the most detailed map ever made of another galaxys magnetism, says Gaensler.
At just 160 000 light-years away the Large Magellanic Cloud, or LMC, is the Milky Ways closest neighbour and is being clawed apart by the Milky Ways gravity. The researchers were surprised that the LMC's magnetic field is so smooth and ordered, given the internal turmoil the galaxy must experience.
Its like having a birthday party all afternoon for a bunch of 4-year-olds, and then finding the house still neat and tidy when they leave, Gaensler says. Some powerful forces must be at work to keep the magnetic field from being messed up.