Term
| which generation stars and galaxies have 74% H and 26% He mass? |
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Definition
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Term
| today we have a matter-dominated universe ruled by what? |
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Definition
|
|
Term
| slight variations in density produces what? |
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Definition
| formation regions for stars and galaxies |
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Term
| the hotter/denser the core the more _______ will pour out |
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Definition
|
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Term
| what are second generation stars like? |
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Definition
|
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Term
| do first generation stars have z? |
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Definition
| yes, but we can't detect it in the spectrum of the star |
|
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Term
| as H and He accrete, gas pressure increases/decreases |
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Definition
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Term
| when gas pressure increases, what does it do to growth? |
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Definition
| it limits it unless there is sufficient matter |
|
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Term
| what is the maximum star mass? |
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Definition
|
|
Term
| what does the Jeans mass equal? |
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Definition
| 10 to the 5th power M(sun) |
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Term
| the Jeans mass constitutes the minimum amount of mass required for what? |
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Definition
| star formation (corresponds to globular star cluster) |
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Term
| collapses of smaller clouds are helped along by what? |
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Definition
1. stochastic processes (wakes of exploding stars or two or more gas clouds merging)
2. compression by magnetic field of galaxy |
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Term
| wakes of exploding stars or two or more gas clouds merging is called what? |
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Definition
|
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Term
| is the universe isogenous or isotropic like Friedmann said? why? |
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Definition
| no - because COBE observed minor variations in temperature from point to point across the sky |
|
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Term
| what four things does the model of the expanding universe work quite well? |
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Definition
1. Olber's paradox
2. X, Y, and Z
3. Hubble's relationship v = HR
4. 2.725K cosmic background radiation |
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Term
| What are three major problems that remain with the standard model of cosmology? |
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Definition
1. flatness problem
2. horizon problem
3. structure problem |
|
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Term
| what does our universe look mostly like today? |
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Definition
| mainly flat but negatively curved |
|
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Term
| what is inflationary cosmology? |
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Definition
| between 10 to the -34th and 10 to the -32 seconds after the big bang, the universe grew exponentially from the size of a nucleon to approximately 85 light years |
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Term
| what solves the three major problems that remain with the standard model of cosmology? |
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Definition
| the inflationary cosmology |
|
|
Term
| did galaxy or star formation come first? |
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Definition
|
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Term
|
Definition
| gravity with a bit of help from various collisions form stars |
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|
Term
| dark matter's presence is deduced from what? |
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Definition
|
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Term
| At the center of a cloud, T increases to what temperature? what does this start? |
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Definition
| it increases to 10 million Kelvin and the proton-proton cycle starts |
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Term
| gravity balanced by radiation pressure for a long period of time depends on what? (birth of a star) |
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Definition
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Term
| Near the end of their lifespan, stars become what? |
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Definition
|
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Term
| what are three possible end states determined by the mass of the star? |
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Definition
1. white dwarf (low mass)
2. neutron star (medium mass)
3. black hole (high mass) |
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Term
| what stars are produced in planetary nebula phase where atmosphere begins a run away process? |
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Definition
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Term
| as earth sized core of a white dwarf is revealed at what temperature? |
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Definition
|
|
Term
| what stars are produced during a supernova explosion resulting in a pulsar? |
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Definition
|
|
Term
| protons and electrons are crushed to produce what? |
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Definition
|
|
Term
| what stars are produced in supernova explosions but neutron degeneracy cannot stop collapse? |
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Definition
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|
Term
| which stars have gravity that is so strong that even light cannot escape? |
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Definition
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Term
| accretion disk (of black holes) are often found in which star systems? |
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Definition
|
|
Term
| what are five ways in which we can detect black holes? |
|
Definition
1. x-ray sources
2. gravitational effects on binary star companion
3. gravitational lensing
4. gravitational ripples
5. accretion disk jets |
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