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Radio astronomy Reference Libraries

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Astrophysics
2014-01-12 00:00:00

Image Caption: 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. Credit: NASA/ESA/Wikipedia What is Astrophysics? For much of the modern age the term Astrophysics has been used synonymously with Astronomy. This interchange is so common that many textbooks even offer the two as...

Radio Telescope
2010-10-08 17:45:24

Radio telescopes, used in tracking and collecting data from satellites and space probes, are a form of directional radio antenna used in radio astronomy. They operate on the radio frequency portion of the electromagnetic spectrum where they detect radio sources. Radio telescopes are large parabolic antennas used singly or in an array and are located far from major centers of population in...

Astronomy
2014-01-12 00:00:00

Sample Entry: Astronomy is the scientific study of stars, planets, comets, galaxies, and other phenomena that occur outside Earth's atmosphere (e.g. cosmic radiation). Astronomy deals with the evolution, physics, chemical makeup, meteorology, and motion of celestial objects, and also the formation of the universe. The word Astronomy comes from the Greek words astron (meaning "star") and...

Zeldovich Yakov Borisovich
2013-03-16 00:00:00

Yakov Borisovich Zel'dovich (March 8, 1914 "“ December 2, 1987) was a productive Soviet physicist. He was instrumental in the advancement of Soviet nuclear and thermonuclear weapons, and also was an invaluable assistance in the fields of adsorption and catalysis, shock waves, nuclear physics, particle physics, astrophysics, physical cosmology, and general relativity. In 1914, he was born...

Radio Telescope
2004-10-19 04:45:43

Radio Telescope -- In contrast to an ordinary telescope, which produces visible light images, a radio telescope "sees" radio waves emitted by radio sources located anywhere in the Universe, typically by means of a large parabolic ("dish") antenna, or arrays of them. The best-known (and largest) radio telescope is in Arecibo, Puerto Rico. A well-known radio telescope being an array of...

Radio Astronomy
2004-10-19 04:45:43

Radio Astronomy -- Radio astronomy is the study of celestial phenomena through measurement of the characteristics of radio waves emitted by physical processes occurring in space. Radio waves are much longer than light waves. In order to receive good signals, radio astronomy requires large antennas. Radio astronomy is a relatively new field of astronomical research. The earliest...

Quasar
2004-10-19 04:45:42

Quasar -- A quasar (from quasi-stellar radio source) is an astronomical object that looks like a star in optical telescopes (i.e. it is a point source), but has a very high redshift. The general consensus is that this high redshift is cosmological, the result of Hubble's law and that their redshift indicates that they are typically very distant from Earth; we observe them as they were...

Cosmic Background Radiation
2004-10-19 04:45:41

Cosmic Background Radiation -- The Big Bang theory predicts that the early universe was a very hot place and that as it expands, the gas within it cools. Thus the universe should be filled with radiation that is literally the remnant heat left over from the Big Bang, called the cosmic microwave background radiation, or CMB. When any patch of the sky is observed where no individual sources...

Active Galaxy
2004-10-19 04:45:41

Active Galaxy -- An active galaxy is a galaxy where a significant fraction of the energy output is not emitted from normal stellar populations or interstellar gas. This energy, depending on the active galaxy type, can be emitted across most of the electromagnetic spectrum, as infrared, radio waves, UV, X-ray and gamma rays. Frequently, the abbreviation AGN (Active Galactic Nuclei) is...

National Radio Astronomy Observatory
2004-10-19 04:45:40

National Radio Astronomy Observatory -- The National Radio Astronomy Observatory (NRAO) is a research facility of the U.S. National Science Foundation. They provide state-of-the-art radio telescope facilities for use by the scientific community. They conceive, design, build, operate and maintain radio telescopes used by scientists from around the world. Scientists use their facilities to...

Word of the Day
sough
  • A murmuring sound; a rushing or whistling sound, like that of the wind; a deep sigh.
  • A gentle breeze; a waft; a breath.
  • Any rumor that engages general attention.
  • A cant or whining mode of speaking, especially in preaching or praying; the chant or recitative characteristic of the old Presbyterians in Scotland.
  • To make a rushing, whistling, or sighing sound; emit a hollow murmur; murmur or sigh like the wind.
  • To breathe in or as in sleep.
  • To utter in a whining or monotonous tone.
According to the OED, from the 16th century, this word is 'almost exclusively Scots and northern dialect until adopted in general literary use in the 19th.'
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