Radioastronomy
Radio astronomy is a subfield of astronomy that studies celestial objects at radio frequencies. These sources of radio emission include stars and galaxies, as well as entirely new classes of objects, such as radio galaxies, quasars, pulsars, and masers. Radio astronomy is conducted using large radio antennas referred to as radio telescopes, that are either used singularly, or with multiple linked telescopes utilizing the techniques of radio interferometry and aperture synthesis. The use of interferometry allows radio astronomy to achieve high angular resolution, as the resolving power of an interferometer is set by the distance between its components, rather than the size of its components.