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The energy source at the center of our galaxy...
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1) Is not visible at optical wavelengths
2) Produces X-rays 3) Must be less than 10 AU in diameter |
In the late 1990s it was announced that the expansion of the universe is accelerating. What doe this imply from the perspective of the Big Bang Theory?
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A force exists that we knew nothing about that causes the acceleration
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The cosmic background radiation comes from a time after the origin of the universe...
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When electrons began to recombine with nuclei to form atoms
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What behavior do galactic rotation curves exhibit to suggest the existence of dark matter in an extended halo?
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Large velocities are seen at large distances from the galactic center
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Which of the following can't be associated with the spiral arms of a galaxy?
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Metal poor stars
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A spiral galaxy contains...
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Upper and lower main sequence stars and gas and dust
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Where did CMB come from?
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Photons released when electrons and nuclei combined for the first time
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Current evidence suggests that the universe is...
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Flat, infinite, and accelerating in its expansion
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The Milky Way Galaxy is a part of...
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The Local Group
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How are astronomers able to determine that quasars are so small?
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They are only found at very large distances
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______ of the Milky Way contains very old stars and globular clusters
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The spiral arms
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The event horizon...
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Has a radius equal to the Schwarzchild radius
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The size of a neutron star
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Smaller than any of these
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Younger stars have heavier elements because...
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The heavy elements were made in previous generations of stars
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_____ galaxies contain large clouds of gas and dust, both young and old stars, but have no obvious spiral arms or nucleus
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Irregular
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