BBC: The supermassive black hole at the center of galaxy Pictor A produces two jets of extremely bright x rays that extend three times the width of the Milky Way. The jets were originally revealed by the Chandra X-Ray Observatory, but what made them so bright could not be determined because the pictures of the galaxy were not of high-enough resolution. Now Martin Hardcastle of the University of Hertfordshire, UK, and his colleagues have combined 15 years of x-ray data from Chandra with radio images created by the Australia Telescope Compact Array. The resulting images, whose resolution is five or six times better than that of the best previous images of Pictor A, reveal new details and allow a better examination of the physics at play in the jets. Based on the images, Hardcastle's team believes that the light being emitted from the jets is caused by electrons that are being accelerated in very tight circles similar to the way they are in synchrotrons on Earth. However, what is causing the electrons to be reaccelerated along the full length of the jets isn't clear.
