Astronomy 1 FINAL Midterm Study (Ch. 21)

24 July 2022
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A. Why do astronomers hypothesize that a massive black hole lies at the center of M87?
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A very small region at the center of M87 releases an enormous amount of energy.
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B. The third image in the video (with the most detailed view of the galactic center) is labeled "gas disk." Which of the following best describes what we are seeing in this photo?
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The black hole is located deep within the bright central region, and around this region we see gas that is orbiting the central black hole.
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C. Assuming that the bright core of M87 is powered by a supermassive black hole, which of the following best describes the source of energy that makes the core appear so bright?
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Gravitational potential energy is converted to thermal energy as matter from the surrounding gas disk spirals into the central black hole.
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A. What typeof galaxy is M82 based on its appearance in the visible-light view?
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irregular
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B. Look again at the visible-light view of M82. What is the source of the white and blue light that dominates the image?
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stars
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C. The infrared image of M82 shows a whitish-blue region running down the center, along with a much larger red region. What is emitting the light that is shown in red, and what is emitting the light that is shown in whitish-blue?
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The red is emission from warm dust grains; the whitish-blue is emission from stars.
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D. Study all of the individual images and the Multi image that combines all of them. Which of the following statements provides the best interpretation of what we see in the Multi image?
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Stars in the central region of this galaxy are exploding as supernovae, generating a galactic wind of hot gas and warm dust grains.
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E. What can we conclude about this galaxy from the fact that there are so many supernovae occurring?
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This galaxy contains an unusually large number of young stars.
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F. As you learned in Part E, galaxy M82 has unusually active star formation. Why do astronomers think that this is a "burst" of star formation, rather than thinking that this galaxy always has such a high rate of star formation?
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At this current rate of star formation, the galaxy would use up all its dust and gas in just a few hundred million years.
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Starburst galaxies
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__________________have the highest rates of star formation.
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central dominant galaxies
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The largest individual galaxies in the universe are known as _______________.
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galactic winds
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The collective activity of many supernova events in a relatively small volume of a galaxy can create ___________________.
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quasars
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The most luminous objects in the universe are _______________.
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supermassive black hole[
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The energy for all active galactic nuclei is thought to come from in-fall of matter into _________________.