GHOSTLY FILAMENTS.  In X-rays, M87 reveals evidence for a series of outbursts from its central black hole. The loops and bubbles in the hot X-ray-emitting gas are relics of small outbursts from close to the black hole. Other interesting features in M87 are narrow filaments of X-ray emission, which may be due to hot gas trapped by magnetic fields. The filament extending below and to the right of the center in almost a straight line is more than 100,000 light-years long.