Term
| as we look at the larger and larger scales in the universe we find |
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Definition
| a larger and lager percentage of matter is dark |
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Term
| according to the HST data very distant and early galaxies tend to be |
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Definition
| smaller, bluer, and more irregular than modern ones |
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Term
| in order for gravitational lensing of a distant quasar to occur, the galaxy producing the lensing must |
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Definition
| be almost perfectly placed on a line between earth and the quasar |
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Term
| which of these is going to happen to the andromeda galaxy |
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Definition
| collision with the milky way |
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Term
| some quasars show absorption spectra with smaller redshift than their emission spectra, this indicates that |
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Definition
| there is cooler gas between us and the quasar |
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Term
| based on galactic rotation curves and cluster dynamics, we think dark matter |
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Definition
| comprises over 90% of the entire mass of the universe |
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Term
| the type of radio galaxy that reveals its motion through the intergalactic medium is called |
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Definition
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Term
| rotation curves for spiral galaxies show |
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Definition
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Term
| in observation of a double quasar image produced by gravitational lensing, fluctuations on the intensity of one image appear to be delayed compared to equivalent variations on the other image, why? |
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Definition
| the optical path through the gravitational lens producing one image is longer than that for the other image |
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Term
| what is believed to be the origen of strburst galaxies |
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Definition
| a recent collision with another galaxy has triggered a wave of star formation |
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Term
| how massive are the largest known glaxies |
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Definition
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Term
| if the merger theory is correct, the brightest active galactic nuclei should |
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Definition
| contain supermassive blackholes |
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Term
| a radio galaxy whose lobes are swept back as if forming a tail probably indicates |
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Definition
| evidence for inter galactic matter |
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Term
| collisions between galaxies |
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Definition
| cause the gas and dust clouds to collide, leading to a rapid star formation |
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Term
| a galaxy that was once a quasar is likely to |
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Definition
| have a black hole at is nucleus |
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Term
| what recent evidence now indicates that several nearby galaxies may contain supermassive black holes at their centers |
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Definition
| spectroscopic observations of stars near the centers of these galaxies, showing extremly high orbital velocities, wich will require large-mass objects to retain in the stars orbit |
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Term
| what is true of spiral galaxies |
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Definition
| they are relatively rare in regions of highly density |
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Term
| collisions between galaxies are thought to |
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Definition
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Term
| astronomers believe that a spiral galaxy may form |
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Definition
| from a collision between a small and large galaxy |
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Term
| gravitational lensing of distant faint irregular galaxies may be the key to |
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Definition
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