Radio sources are objects in outer space that emit strong radio waves. Radio emission comes from hot gas, electrons spiralling in magnetic fields and specific wavelengths emitted by atoms and molecules in space. Layers of Atmosphere - not to scale (NOAA) Outer space, also called just space, refers to the relatively empty regions of the Universe outside the atmospheres of celestial bodies. ... Radio frequency, or RF, refers to that portion of the electromagnetic spectrum in which electromagnetic waves can be generated by alternating current fed to an antenna. ... A gas is one of the four main phases of matter (after solid and liquid, and followed by plasma), that subsequently appear as a solid material is subjected to increasingly higher temperatures. ... Properties The electron (also called negatron, commonly represented as e−) is a subatomic particle. ... Current flowing through a wire produces a magnetic field (M) around the wire. ... Properties For alternative meanings see atom (disambiguation). ... In science, a molecule is the smallest particle of a pure chemical substance that still retains its chemical composition and properties. ...

In 1932, radio astronomer, Karl Jansky detected radio waves coming from an unknown source in the centre of our galaxy. Other strong radio sources have been the remains of a supernova explosion in the Crab Nebula and pulsars. Short radio waves have come from complex molecules in dense clouds of gas where stars are giving birth. Searches have been taken to find out if there are other civilizations in our galaxy using radio waves, but have had no successes. An astronomer or astrophysicist is a scientist whose area of research is astronomy or astrophysics. ... Radio frequency, or RF, refers to that portion of the electromagnetic spectrum in which electromagnetic waves can be generated by alternating current fed to an antenna. ... NGC 4414, a typical spiral galaxy in the constellation Coma Berenices, is about 56,000 light years in diameter and approximately 60 million light years distant. ... Multiwavelength X-ray image of the remnant of Keplers Supernova, SN 1604. ... Composite Optical/X-ray image of the Crab Nebula pulsar, showing surrounding nebular gases stirred by the pulsars magnetic field and radiation. ... Radio frequency, or RF, refers to that portion of the electromagnetic spectrum in which electromagnetic waves can be generated by alternating current fed to an antenna. ... In science, a molecule is the smallest particle of a pure chemical substance that still retains its chemical composition and properties. ... A gas is one of the four main phases of matter (after solid and liquid, and followed by plasma), that subsequently appear as a solid material is subjected to increasingly higher temperatures. ... For alternate meanings see star (disambiguation) Hundreds of stars are visible in this image taken by the Hubble Space Telescope of the Sagittarius Star Cloud in the Milky Way Galaxy. ... NGC 4414, a typical spiral galaxy in the constellation Coma Berenices, is about 56,000 light years in diameter and approximately 60 million light years distant. ... Radio frequency, or RF, refers to that portion of the electromagnetic spectrum in which electromagnetic waves can be generated by alternating current fed to an antenna. ...

There are many sources of radio waves beyond our galaxy, most of which are found in other galaxies. A few examples include neutral hydrogen and carbon monoxide, mostly found in spiral galaxies, and quasars (short for "quasi-stellar radio source"), which are point-like sources of radio waves and other kinds of electromagnetic radiation that are thought to be powered by supermassive black holes in the centers of elliptical galaxies. Scientists have also discovered weak background radiation left over from the Big Bang (the rapid expanion, roughly 13.7 billion years ago, that was the beginning of our universe). Radio frequency, or RF, refers to that portion of the electromagnetic spectrum in which electromagnetic waves can be generated by alternating current fed to an antenna. ... NGC 4414, a typical spiral galaxy in the constellation Coma Berenices, is about 56,000 light years in diameter and approximately 60 million light years distant. ... The hydrogen line refers to the spectral line created by changes in the energy state of neutral hydrogen and occurs at 1420. ... Carbon monoxide, chemical formula CO, is a colourless, odourless, tasteless, flammable and highly toxic gas. ... A spiral galaxy is a type of galaxy in the Hubble sequence which is characterized by the following physical properties: Spiral Galaxy M74 presents a face-on view of its spiral arms. ... This view, taken with infrared light, is a false-color image of a quasar-starburst tandem with the most luminous starburst ever seen in such a combination. ... Electromagnetic radiation can be conceptualized as a self propagating transverse oscillating wave of electric and magnetic fields. ... Top: artists conception of a supermassive black hole drawing material from a nearby star. ... An elliptical galaxy is a type of galaxy in the Hubble sequence characterized by the following physical properties: The giant elliptical galaxy NGC 4881 (the spherical glow at upper left) lies at the edge of the Coma Cluster of Galaxies. ... Background radiation is the ionizing radiation from several natural radiation sources: sources in the Earth and from those sources that are incorporated in our food and water, which are incorporated in our body, and in building materials and other products that incorporate those radioactive sources; radiation sources from space (in... According to the Big Bang theory, the Universe originated in an extremely dense and hot state (bottom). ... The deepest visible-light image of the cosmos. ...