Question 1

What evidence suggests that supermassive black holes are at the center of most large galaxies?

Accepted Answer

Rapid fluctuations in the brightness of ...

Question 2

There are two distinct period-luminosity relations,Type I and Type II.

Accepted Answer

A)   Type I is metal rich and more luminous.
B)   Type II is metal rich and more luminous.
C)   Type I is metal poor and more luminous.
D)   Type II is metal poor and more luminous.E) None of the above
F) A) and C)

Question 3

How were quasars discovered?

Accepted Answer

Some strange objects had radio wave sour...

Question 4

What would happen if the Andromeda Galaxy (a spiral about the same size as ours) collided with our own Milky Way Galaxy?

Accepted Answer

A)   The two galaxies would pass through each other,the stars sailing past one another unharmed,while the interstellar gas and dust clouds would collide and stop,thereby becoming extremely heated.
B)   The two galaxies would pass through each other almost unchanged,with essentially no interactions at all.
C)   The supermassive black holes of the two galaxies would collide and explode,the resulting radiation essentially destroying their stars,planets,and any life forms that there may have been (including us) .
D)   All of the gas and dust clouds and a great many of the stars would collide with each other,stopping both galaxies and creating a galactic merger.E) A) and C)
F) A) and B)

Question 5

Which of these distance-measuring techniques works for the farthest objects?

Accepted Answer

A)   Parallax
B)   Supernovae Ia
C)   Tully-Fisher
D)   Cepheid variablesE) B) and D)
F) A) and B)

Question 6

The Tully-Fisher relation provides a method of determining distances to galaxies by estimating the galaxy luminosity from the measurement of what parameter relating to the 21-centimeter atomic hydrogen radio emission line?

Accepted Answer

A)   Its position and Doppler shift
B)   The split between its two components
C)   Its width
D)   Its intensityE) None of the above
F) All of the above

Question 7

Rapid fluctuations in the brightness of active galaxies indicate that the region that emits radiation is quite small.

Accepted Answer

A) True 
 B)False

Question 8

Why do we find a larger percentage of spiral galaxies in distant clusters compared to nearby clusters?

Accepted Answer

A)   Distant clusters are younger,and this contrast in the percentage of spirals shows evidence for the natural evolution of spirals into ellipticals.
B)   Distant clusters are older,and this contrast in the percentage of spirals shows evidence for the natural evolution of ellipticals into spirals.
C)   Over time,galactic collisions and mergers have destroyed many of the spiral arms that give spirals their distinctive appearance.
D)   Spirals contain more gas and dust than ellipticals.In older,nearby clusters,less gas and dust remain and fewer spirals are created.E) None of the above
F) B) and C)

Question 9

In the Hubble classification scheme for spiral galaxies,the tightness of the winding of the spiral arms appears to be directly related to the

Accepted Answer

A)   overall intrinsic size of the galaxy,or the diameter across the spiral arms.
B)   number of globular clusters in the halo of the galaxy.
C)   age of the galaxy,as determined from the age of its individual stars.
D)   size of the central bulge of the galaxy.E) B) and C)
F) A) and D)

Question 10

In observations of a double-quasar image produced by gravitational lensing,fluctuations on the intensity of one image appear to be delayed compared to equivalent variations on the other image.Why is this?

Accepted Answer

A)   Rotation of the lensing galaxy has delayed the beam of light on one side compared to the other because of the Doppler effect.
B)   One beam has had to pass through material with a greater refractive index than the other beam within the lensing galaxy.
C)   The gravitational field of the lensing object slows down the light on one beam compared to the other.
D)   The optical path through the gravitational lens producing one image is longer than that for the other image.E) C) and D)
F) A) and C)

Question 11

Compared to an E4,an E0 elliptical galaxy appears to

Accepted Answer

A)   be much smaller.
B)   be much larger.
C)   be nearly perfectly circular.
D)   rotate clockwise.E) C) and D)
F) B) and D)

Question 12

What determines whether a protogalaxy evolves into a spiral or an elliptical galaxy?

Accepted Answer

The rate at which stars form within a pr...

Question 13

The energy generation mechanism for active galaxies is believed to be

Accepted Answer

A)   large numbers of supernovae erupting simultaneously.
B)   cosmic radioactive decay.
C)   black holes colliding.
D)   accretion disks around supermassive black holes.E) A) and D)
F) A) and C)

Question 14

Which one of the following statements is TRUE about clusters of galaxies?

Accepted Answer

A)   The mass observed in the galaxies of the cluster is about 10 times larger than the amount needed to hold the cluster together,causing the cluster to collapse.
B)   The mass observed in the galaxies of the cluster is typically almost exactly equal to that needed to hold the cluster together.
C)   The mass observed in the galaxies of the cluster is many thousands of times too small to hold the cluster together.
D)   The mass observed in the galaxies of the cluster is about 10 times too small to hold the cluster together.E) None of the above
F) A) and C)

Question 15

Which of the following statements is NOT characteristic of elliptical galaxies?

Accepted Answer

A)   They are almost devoid of interstellar gas and dust.
B)   They stopped forming stars billions of years ago.
C)   Different elliptical galaxies appear to be flattened by different amounts.
D)   They have a disk and central bulge,but no spiral arms.E) A) and B)
F) B) and C)

Question 16

What is gravitational lensing and what can it be used to detect in astronomy?

Accepted Answer

Gravitational lensing is when an object ...

Question 17

The Tully-Fisher relation can be used for measuring distance.

Accepted Answer

A) True 
 B)False

Question 18

A barred spiral galaxy has young,hot,blue stars in its disk.

Accepted Answer

A) True 
 B)False

Question 19

At the conclusion of the Shapley-Curtis debate in April 1920,the general understanding of the astronomical community toward the "spiral nebulae" was

Accepted Answer

A)   that the "spiral nebulae" were part of the Milky Way Galaxy.
B)   that the "spiral nebulae" were distant island universes like the Milky Way Galaxy.
C)   still inconclusive.
D)   that some "spiral nebulae" were within the Milky Way Galaxy and others were far outside it.E) B) and C)
F) A) and D)

Question 20

The following distance-measuring techniques,arranged in order of the distance for which they are most effective,from smallest to greatest,are

Accepted Answer

A)   Cepheid variables,spectroscopic parallax,Type Ia supernovae,Tully-Fisher relation.
B)   Spectroscopic parallax,Tully-Fisher relation,Cepheid variables,Type Ia supernovae.
C)   Spectroscopic parallax,Cepheid variables,Tully-Fisher relation,Type Ia supernovae.
D)   Cepheid variables,spectroscopic variables,Type Ia supernovae,Tully-Fisher relation.E) A) and B)
F) A) and C)

Exam 14: Investigating Other Galaxies

Which of these distance-measuring techniques works for the farthest objects?

Correct AnswerverifiedShow Answer

At the conclusion of the Shapley-Curtis debate in April 1920,the general understanding of the astronomical community toward the "spiral nebulae" was

Correct AnswerverifiedShow Answer

Which of the following statements is NOT characteristic of elliptical galaxies?

Correct AnswerverifiedShow Answer

What would happen if the Andromeda Galaxy (a spiral about the same size as ours) collided with our own Milky Way Galaxy?

Correct AnswerverifiedShow Answer

There are two distinct period-luminosity relations,Type I and Type II.

Correct AnswerverifiedShow Answer

What evidence suggests that supermassive black holes are at the center of most large galaxies?

Correct AnswerverifiedRapid fluctuations in the brightness of ...View AnswerShow Answer

What is gravitational lensing and what can it be used to detect in astronomy?

Correct AnswerverifiedGravitational lensing is when an object ...View AnswerShow Answer

How were quasars discovered?

Correct AnswerverifiedSome strange objects had radio wave sour...View AnswerShow Answer

A barred spiral galaxy has young,hot,blue stars in its disk.

Correct AnswerverifiedShow Answer

Compared to an E4,an E0 elliptical galaxy appears to

Correct AnswerverifiedShow Answer

The Tully-Fisher relation can be used for measuring distance.

Correct AnswerverifiedShow Answer

The Tully-Fisher relation provides a method of determining distances to galaxies by estimating the galaxy luminosity from the measurement of what parameter relating to the 21-centimeter atomic hydrogen radio emission line?

Correct AnswerverifiedShow Answer

The energy generation mechanism for active galaxies is believed to be

Correct AnswerverifiedShow Answer

Rapid fluctuations in the brightness of active galaxies indicate that the region that emits radiation is quite small.

Correct AnswerverifiedShow Answer

Why do we find a larger percentage of spiral galaxies in distant clusters compared to nearby clusters?

Correct AnswerverifiedShow Answer

The following distance-measuring techniques,arranged in order of the distance for which they are most effective,from smallest to greatest,are

Correct AnswerverifiedShow Answer

What determines whether a protogalaxy evolves into a spiral or an elliptical galaxy?

Correct AnswerverifiedThe rate at which stars form within a pr...View AnswerShow Answer

Which one of the following statements is TRUE about clusters of galaxies?

Correct AnswerverifiedShow Answer

In the Hubble classification scheme for spiral galaxies,the tightness of the winding of the spiral arms appears to be directly related to the

Correct AnswerverifiedShow Answer

In observations of a double-quasar image produced by gravitational lensing,fluctuations on the intensity of one image appear to be delayed compared to equivalent variations on the other image.Why is this?

Correct AnswerverifiedShow Answer

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Rapid fluctuations in the brightness of ...
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Gravitational lensing is when an object ...
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Some strange objects had radio wave sour...
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The rate at which stars form within a pr...
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