Motion of cosmic strings in a gas

The behavior of a gaseous medium in the gravitational field of a moving cosmic string is considered. This problem is shown to be mathematically equivalent to the classical gas-dynamic problem of supersonic motion of a sharp wedge. Estimates of the energy release in the shock wave that arises behind the string are made. The possibility of detecting strings as they pass through the intergalactic gas in clusters of galaxies and through interstellar gas in the Galaxy is discussed