There is
a pulsar near the black hole at the center of the Milky Way galaxy in which we live.
As radio waves travel from the pulsar toward Earth, they encounter magnetic fields generated by clouds of gas getting pulled in by the Milky Way’s central supermassive black hole, called Sagittarius A*. The fields twist the radio waves, which initially oscillated in one direction, into corkscrews.
By measuring this twisting effect, the researchers determined that the magnetic field around Sagittarius A* is relatively strong. Roughly 150 light-years from the black hole’s core, the field is only one-hundredth of the strength of the magnetic field around Earth. But the researchers estimate that the field likely strengthens by five orders of magnitude just outside Sagittarius A*’s core.
Reference: R. P. Eatough et al. A strong magnetic field around the supermassive black hole at the center of the galaxy. Nature. August 15, 2013. doi:10.1038/nature12499.
No comments:
Post a Comment