The material of particles, gas, and dust, between stars. The portion of the ISM we care about are the free electrons because of the dispersive delay (see dispersion measure) along with other effects due to radio propagation through the medium.
The material of particles, gas, and dust, between stars. The portion of the ISM we care about are the free electrons because of the dispersive delay (see dispersion measure) along with other effects due to radio propagation through the medium.