exam3astronomy - How do you weigh a galaxy-Measuring the...

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What are some of the ways to measure distances to galaxies? (pg 610) - sepheid, distance change summary The further away the object the faster it moves…? (618) What is woodback time? (621) - the amount of time since the light we see from a distant object was emitted What makes a starburst galaxy unique, what does it do? (634) - They from stars so quickly that it uses all its gas in less than a billion years What is a quasar? (637) - Brightest type of active galactic nucleus What is dark matter? - An undetected form of mass that emits little or no light and you can infer its existence from its gravitational influence - Only 23% of the unvierse What is dark energy? - An unknown form of energy that seems to be the source of a repulsive force causing the expansion of the universe to accelerate - 73% of universe
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Unformatted text preview: How do you weigh a galaxy?-Measuring the orbital velocity What are three ways galaxy clusters reveal dark matter?-Section of pg 654-Measuring the speeds of galaxies orbiting the center of the cluster, x-ray emissions from the hot gas between the clusters galaxies and observing how the cluster bend light as gravitational lenses What is baryonic matter?-Ordinary matter What’s a macho?-Dim star like objects What’s a wimp?-Non-baryonic matter and are subatomic particles There are expanding patterns; what are they?-recollapsing, accelerating, critical, coasting (665) At what rate is the universe expanding?-decelerating What is critical density?-Precise average density marking the dividing line between eternal expansion and eventual collapse...
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This note was uploaded on 08/30/2011 for the course COMM 1014 taught by Professor Bmwaggenspack during the Spring '06 term at Virginia Tech.

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exam3astronomy - How do you weigh a galaxy-Measuring the...

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