Term
| how many stars do galaxies consist of? |
|
Definition
| a few thousand to tens of billions |
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Term
| What is the Hubble Deep Field an image of? |
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Definition
| thousands of distant galaxies |
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Term
| What is the shape of EO galaxies? E7 galaxies? |
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Definition
| EO are spherical, E7 are highly elliptical |
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Term
| What type of nucleus does an Sa galaxy have? Sc? |
|
Definition
| Sa nucleus is large, Sc is small nucleus |
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Term
| Sa galaxies have what kind of arms? Sc? |
|
Definition
Sa have tightly wound arms
Sc have loose arms |
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Term
| A galaxy with a disk and a bulge but with no gas is classified as? |
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Definition
|
|
Term
| What are spiral galaxies with a bar in the center called? |
|
Definition
|
|
Term
| What are three types of irregular galaxies? |
|
Definition
1. starburst galaxies
2. dwarf galaxies |
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Term
| what do standard candles tell us? when compared to apparent magnitude, what do they help us find? |
|
Definition
| the absolute magnitude, distance |
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Term
| what do we use to measure the distances of the farthest galaxies? |
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Definition
|
|
Term
| what two things can we study to determine the mass of a galaxy? |
|
Definition
| rotation curves and keplers 3rd law |
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Term
| Most galaxies have what in the center? |
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Definition
|
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Term
| Most of the mass in a galaxy is visible or invisible? |
|
Definition
|
|
Term
| what three are the visible mass in the galaxy? |
|
Definition
| stars, interstellar gas, and dust |
|
|
Term
| what is the invisible mass made up of? |
|
Definition
| brown dwarves, small black holes, elemetary particles |
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|
Term
| What is one method of detecting dark matter? |
|
Definition
| by observing gravitational lensing |
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|
Term
| true or false. Galaxies exist in isolation. |
|
Definition
|
|
Term
| How many galaxies do rich clusters usually have? Are they or are they not centered on a large galaxy? |
|
Definition
| more than 1000 and are centered on a large galaxy |
|
|
Term
| How many galaxies do poor clusters usually have? Are they or are they not centered around large galaxies? |
|
Definition
| are not centered around large galaxies and less than 1000 |
|
|
Term
| what is our galaxy cluster called? |
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Definition
|
|
Term
| what is the milky way currently ripping apart? |
|
Definition
| the Canis Major Dwarf galaxy |
|
|
Term
| what three objects do we observe when galaxies collide or interact? |
|
Definition
1. ring galaxies
2. tidal tails
3. starburst galaxies |
|
|
Term
| what is the evidence of the collision of galaxies NGC 7252? |
|
Definition
| evidence of mergers of galaxies |
|
|
Term
| what is the multiple nuclei in giant elliptical galaxies evidence of? |
|
Definition
|
|
Term
| what are starburst galaxies? |
|
Definition
| galaxies where stars are being born at a high rate |
|
|
Term
| what do galaxies look like through 19th century telescopes? |
|
Definition
|
|
Term
| what three classes are galaxies divided into? |
|
Definition
| elliptical, sprial and irregular |
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|
Term
| Elliptical galaxies can't make new what? |
|
Definition
|
|
Term
| What measurement do astronomers use to measure distances? |
|
Definition
|
|
Term
|
Definition
| the apparent velocity of recession of galaxy equals the distance times the hubble constant V=DxHC |
|
|
Term
| what does the rotation curve of a galaxy show? |
|
Definition
| the orbital motion of its stars |
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|
Term
| What term describes how larger galaxies can absorb smaller galaxies? |
|
Definition
|
|
Term
| how are ring galaxies produced? |
|
Definition
| by high-speed collisions where small galaxy plunges through larger galaxy perpendicular to disk |
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