Galaxies - Quiz 16

1. .A large galaxy contains mostly old (Pop II) stars spread smoothly throughout its volume, but it has little dust or gas. What type galaxy is it most likely to be?
A).. Irr
C).. SB
E)..All of the above are possible.

2. A galaxy's spectrum has a redshift of 30,000 kilometers per second. If the Hubble constant is 75 kilometers per second per megaparsec, how far away from Earth is the galaxy?
A)...106 megaparsecs
B)... 1000 megaparsecs
C)...20 megaparsecs
D)...50 megaparsecs
E)...400 megaparsecs

3.The Local Group
A)... contains about 30 member galaxies.
B)... is a poor cluster.
C)... is the galaxy cluster to which the Milky Way belongs.
D) a rich cluster.
E)... is all of the above except (D).

4. A spiral galaxy has a small bright central region and its spectrum shows that it contains hot, rapidly moving gas. It is most likely a ____________ galaxy.
A)... barred spiral
B)... Seyfert
C)... radio
D)... BL Lac
E)... quasar

5. Astronomers believe that dark matter exists because
A)... they can detect it with radio telescopes.
B)... the outer parts of galaxies rotate faster than expected on the basis of the material visible in them.
C)... the galaxies in clusters move faster than expected on the basis of the material visible in them.
D)... it is the only way to explain the black holes in active galaxies.
E)... Both (B) and (C) are correct.

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