FERMI satellite hunts for extremely long wavelength gravitational wave signals

Coalescing supermassive black holes in the centers of merging galaxies fill the universe with low-frequency gravitational waves. Astronomers have been searching for these waves by using large radio telescopes to look for the subtle effect these spacetime ripples have on radio waves emitted by pulsars within our galaxy. Now, an international team of scientists has shown that the high-energy light collected by NASA's Fermi Gamma-ray Space Telescope can also be used in the search. Using gamma rays ...