Normal and Active Galaxies
Learning Objectives
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Describe the basic properties of the main types of normal galaxies. |
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Discuss the distance-measurement techniques that enable astronomers to map the universe beyond the Milky Way. |
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Describe how galaxies clump into clusters. |
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State Hubble’s law and explain how it is used to derive distances to the most remote objects in the observable universe. |
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Specify the basic differences between active and normal galaxies. |
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Describe the important features of active galaxies. |
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Explain what drives the central engine thought to power all active galaxies. |