Astronomy Ch.13 (Galaxies: Normal & Active) Crossword
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Down:
2) the combined calibration of distance indicators used by astronomers to find the distance to remote galaxies 3) a galaxy that resembles a ring around a bright nucleus, believed to be the result of a head-on collision of two galaxies 4) a measure of the rate of expansion of the universe, the average value of velocity of recession divided by distance, presently believed to be about 70 km/s/mpc6) the process by which the gravitational field of a massive object focuses the light from a distant object to produce multiple images of the distant object or to make the distant object look brighter7) a galaxy that is a strong source of radio signals8) the theory that double radio lobes are produced by pairs of jets emitted in opposite directions from the centers of active galaxies 9) the amount by which you look into the past when you look at a distant galaxy; a time equal to the distance to the galaxy in light-years11) a unit of distance equal to 1,000,000 pc15) the linear relation between the distances to galaxies and their velocity of recession17) the small cluster of a few dozen galaxies that contains our Milky Way Galaxy18) small, powerful source of energy believed to be the active core of a very distance galaxy23) a galaxy whose center emits large amounts of excess energy, often in the form of radio emission. active galaxies are suspected of having massive black holes in their centers into which matter is flowing |
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1) a method of determining a galaxy's mass by observing the orbital velocities and radius of the orbits of stars in the galaxy 5) a graph of orbital velocity versus radius in the disk of a galaxy10) a galaxy that emits radio energy from two regions (lobes) located on opposite sides of the galaxy12) a long streamer of stars, gas, and dust torn from a galaxy during its close interaction with another passing galaxy13) the theory that large galaxies absorb smaller galaxies14) an attempt to explain the different types of active galactic nuclei using a single model viewed from different directions 16) a galaxy with an obvious disk component containing gas; dust; hot, bright stars; and spiral arms19) a galaxy undergoing a rapid burst of star formation 20) a cluster containing over 1000 galaxies mostly elliptical, scattered over a volume about 3 Mpc in diameter 21) a galaxy with a chaotic appearance, large clouds of gas and dust, and both population I and II stars, but without spiral arms22) in radio astronomy, a bright spot in a radio lobe24) a galaxy that is round or elliptical in outline and contains little gas and dust, no disk or spiral arms, and few hot, bright stars25) objects whose luminosity or diameter is known, used to find the distance to a star cluster or galaxy26) object of known brightness that astronomers use to find distance -- for example, Cepheid variable stars and supernovae27) the centers of active galaxies that are emitting large amounts of excess energy 28) a spiral galaxy with an elongated nucleus resembling a bar from which the arms originate 29) an otherwise normal spiral galaxy with an unusually bright, small core that fluctuates in brightness, believed to indicate that the core is erupting 30) an irregularly shaped cluster that contains fewer than 1000 galaxies, many of which are spiral, and with no giant ellipticals |
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