Question 1

Because t he Hubble constant has a value of 70 km/s/Mpc, a galaxy 100 Mpc away would have a recession velocity of ____.

Accepted Answer

A)   0.7 km/s
B)   1.43 km/s
C)   30 km/s
D)   170 km/s
E)   7,000 km/sF) B) and E)
G) D) and E)

Question 2

Active galaxies are the result of galactic _______________.

Accepted Answer

collisions,interacti...

Question 3

Double-lobed radio galaxies are____.

Accepted Answer

A)   spiral galaxies with unusually luminous nuclei
B)   elliptical galaxies with very broad emission lines
C)   explained by the double-exhaust model
D)   extremely luminous objects with high redshifts
E)   glowing green gases due to excitation from energy from an active coreF) A) and E)
G) C) and D)

Question 4

What is the cause of the lobes in a double-lobed radio galaxy?

Accepted Answer

Jets from a central ...

Question 5

What direct evidence is there for galactic collisions? Discuss examples of directly observable phenomena linked to collisions.

Accepted Answer

The gravitational field of one galaxy ca...

Question 6

Quasars are common in the early Universe because ____ at that time.

Accepted Answer

A)   galactic collisions were more frequent
B)   black hole collisions were more frequent
C)   gas and dust clouds were denser
D)   galaxies were more isolated
E)   central bulges were largerF) A) and B)
G) C) and D)

Question 7

The size of a galaxy's central black hole is proportional to the mass of its disk.

Accepted Answer

A) True 
 B)False

Question 8

Figure 16-1 
Most quasars have a redshift of ____.

Accepted Answer

A)   less than 1.0
B)   between 1.0 and 2.0
C)   between 2.0 and 3.0
D)   between 3.0 and 4.0
E)   greater than 4.0F) A) and D)
G) A) and B)

Question 9

Quasars are caused by galaxy collisions in the early Universe.

Accepted Answer

A) True 
 B)False

Question 10

Normal galaxies in the present never went through an active galaxy phase.

Accepted Answer

A) True 
 B)False

Question 11

Hubble's law is only effective in measuring the distance to nearby galaxies.

Accepted Answer

A) True 
 B)False

Question 12

Matter falling into a black hole arranges itself in the shape of a ____.

Accepted Answer

A)   spherical shell that is thick at the edges and thin closer to the center
B)   spherical shell that is thin at the edges and thick closer to the center
C)   disk that is thick at the outer edge, thin along the inner ring
D)   disk that is thin at the outer edge and thick closer to the center
E)   disk that is thin from the outer edge to the centerF) C) and E)
G) B) and E)

Question 13

Because the Hubble constant has a value of 70 km/s/Mpc, a galaxy 50 Mpc away would have a recession velocity of _______________ km/s. (Round your answer to the nearest 1 km/s).

Accepted Answer

The answer of Because the Hubble constant has a value...

Question 14

Because the Hubble constant has a value of 70 km/s/Mpc, a galaxy with a recession velocity of 21,000 km/s must be _______________ Mpc from Earth. (Express your answer as a whole number of Mpc)

Accepted Answer

The answer of Because the Hubble constant has a value...

Question 15

Why do astronomers conclude that quasars are very far away?

Accepted Answer

The spectra of quasars have ve...

Question 16

Rich galactic clusters ____.

Accepted Answer

A)   are rare, because galaxies are usually isolated in space
B)   contain gas that is rich in metals
C)   are composed of mostly elliptical galaxies
D)   are very spread out, without a defined center
E)   contain a wide variety of galaxy types and sizesF) A) and E)
G) A) and C)

Question 17

In the unified model, an accretion disk viewed from the side will cause ____ to be present in the spectrum of a Seyfert galaxy.

Accepted Answer

A)   narrow absorption lines
B)   broad absorption lines
C)   narrow spectral lines
D)   broad emission lines
E)   no absorption linesF) A) and C)
G) B) and C)

Question 18

In which of the following types of galaxies would you expect to find active star formation?

Accepted Answer

A)   elliptical galaxies only
B)   elliptical and spiral galaxies
C)   spiral galaxies only
D)   elliptical and irregular galaxies
E)   spiral and irregular galaxiesF) A) and E)
G) A) and B)

Question 19

A supermassive black hole in the center of a galaxy typically represents ____ of the galaxy's total mass.

Accepted Answer

A)   a tiny fraction of a percent
B)   about a percent
C)   1-5%
D)   10%
E)   50%F) A) and B)
G) A) and C)

Question 20

Quasars ____.

Accepted Answer

A)   are common at all ages of the Universe
B)   are the early stages of what become Seyfert galaxies
C)   disrupt galactic formation and become isolated black holes
D)   are an early stage of the formation of common galaxies
E)   are formed from double-lobed radio galaxiesF) A) and B)
G) D) and E)

Exam 16: Galaxies

Figure 16-1 Most quasars have a redshift of ____.

Correct AnswerverifiedShow Answer

Because the Hubble constant has a value of 70 km/s/Mpc, a galaxy 50 Mpc away would have a recession velocity of _______________ km/s. (Round your answer to the nearest 1 km/s).

Correct AnswerverifiedShow Answer

Because t he Hubble constant has a value of 70 km/s/Mpc, a galaxy 100 Mpc away would have a recession velocity of ____.

Correct AnswerverifiedShow Answer

A supermassive black hole in the center of a galaxy typically represents ____ of the galaxy's total mass.

Correct AnswerverifiedShow Answer

Hubble's law is only effective in measuring the distance to nearby galaxies.

Correct AnswerverifiedShow Answer

Rich galactic clusters ____.

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Normal galaxies in the present never went through an active galaxy phase.

Correct AnswerverifiedShow Answer

Why do astronomers conclude that quasars are very far away?

Correct AnswerverifiedThe spectra of quasars have ve...View AnswerShow Answer

What is the cause of the lobes in a double-lobed radio galaxy?

Correct AnswerverifiedJets from a central ...View AnswerShow Answer

Matter falling into a black hole arranges itself in the shape of a ____.

Correct AnswerverifiedShow Answer

In which of the following types of galaxies would you expect to find active star formation?

Correct AnswerverifiedShow Answer

In the unified model, an accretion disk viewed from the side will cause ____ to be present in the spectrum of a Seyfert galaxy.

Correct AnswerverifiedShow Answer

Quasars are caused by galaxy collisions in the early Universe.

Correct AnswerverifiedShow Answer

What direct evidence is there for galactic collisions? Discuss examples of directly observable phenomena linked to collisions.

Correct AnswerverifiedThe gravitational field of one galaxy ca...View AnswerShow Answer

Active galaxies are the result of galactic _______________.

Correct Answerverifiedcollisions,interacti...View AnswerShow Answer

Quasars are common in the early Universe because ____ at that time.

Correct AnswerverifiedShow Answer

Because the Hubble constant has a value of 70 km/s/Mpc, a galaxy with a recession velocity of 21,000 km/s must be _______________ Mpc from Earth. (Express your answer as a whole number of Mpc)

Correct AnswerverifiedShow Answer

Double-lobed radio galaxies are____.

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Quasars ____.

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The size of a galaxy's central black hole is proportional to the mass of its disk.

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The spectra of quasars have ve...
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Jets from a central ...
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The gravitational field of one galaxy ca...
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collisions,interacti...
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