Sonic booms may shape cosmic strings

Space.com : Astronomers in France have observed images of cosmic filaments, strings of gas in nearby clouds between stars in our galaxy, and believe that they may have been shaped by interstellar sonic booms. New photos from the European Space Agency’s Herschel Space Observatory have allowed astronomers to measure the widths of the filaments for the first time. They have found that no matter how long or dense the filament, its width is always about the same. Doris Arzoumanian, of the Laboratoire AIM Paris-Saclay, and colleagues have sought an explanation for this consistency. Comparing the observations with computer models, they have concluded that the filaments are probably formed when shockwavespossibly caused by exploding starsdissipate in the interstellar clouds, compressing and sweeping up gas found in the galaxy. “The connection between these filaments and star formation used to be unclear, but now thanks to Herschel, we can actually see stars forming like beads on strings in some of these filaments,” said Göran Pilbratt, ESA Herschel project scientist.