Are highly magnetized rotating neutron stars which

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____________ are highly magnetized rotating neutron stars which emit a beam of detectable electromagnetic radiation in the form of radio waves. Explanation: Pulsars. The radiation can only be observed when the beam of emission is pointing towards the Earth. Most pulsars actually are detectable only by their radio radiation--they release too little visible light to be seen with the human eye. Because neutron stars are very dense objects, the rotation period and the interval between observed pulses are very regular. A ____________ is an extremely bright and distant active galactic nucleus--the very bright center of a distant galaxy powered by a black hole in the galaxy in which it's located. : Quasar. Quasars were first identified as high redshift sources of electromagnetic energy including radio waves and visible light. They are considered the most distant objects discovered by astronomers, so far away that their light takes billions of years to reach the Earth. For this reason, the study of quasars gives astronomers a glimpse into the early stages of the universe. They radiate enormous amounts of energy and are the most luminous objects ever detected, some being as much as a trillion times brighter than our sun. The currently accepted definition is that a quasar is a compact halo of matter surrounding the central supermassive black hole of a young galaxy. ____________ occurs when the frequency of a photon of light is shifted towards the red end of the electromagnetic spectrum. : Redshift. A shift towards the red end of the spectrum indicates lower energy, which means longer wavelength. As you have learned earlier, one instance in which redshift is observed is when a light-emitting object (such as a distant galaxy) is moving further away. As it moves away, the wavelength of the light is stretched out, causing the light to shift towards red. On the other hand, if the source of the light were moving closer, blueshift would result as the wavelength of the light gets compressed (higher energy, higher frequency, lower wavelength)
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_______________ redshift is caused by the expansion of the universe. : Cosmological. As the light is moving from its point of emission (i.e. a distant galaxy) to the point of detection (i.e. Earth), the fact that the universe is expanding and the space between the point of emission and detection is increasing results in an increase in the wavelength of the light (lower energy, a shift towards red). Just picture the light, which is taking millions of years to arrive at your telescope, is being stretched as the universe it is passing through is stretching. This will obviously result in a longer wavelength. A ________________ black hole has a mass of up to tens of billions of solar masses. Explanation: Supermassive. It is believed that all galaxies contain supermassive black holes at their galactic centers. Two supermassive black holes can co-exist in the same galaxy for a certain amount of time.
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