Powerful but unknown forces are at work in a small companion galaxy of the Milky Way, astronomers say in todayÂ’s issue of the journal Science.
Something is keeping the structure and magnetic field of this galaxyÂ—the Large Magellanic CloudÂ—strong and ordered, even while the Milky WayÂ’s 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 galaxyÂ’s magnetic field.
Â“This is the most detailed map ever made of another galaxyÂ’s magnetism,Â” says Gaensler.
At just 160 000 light-years away the Large Magellanic Cloud, or LMC, is the Milky WayÂ’s closest neighbour and is being clawed apart by the Milky WayÂ’s gravity. The researchers were surprised that the LMC's magnetic field is so smooth and ordered, given the internal turmoil the galaxy must experience.
Â“ItÂ’s 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,Â” Gaensler says. Â“Some powerful forces must be at work to keep the magnetic field from being messed up.Â”