Question 1

The Milky Way is often considered to be an intermediately wound, barred spiral, whichwould be type ________ according to Hubble.

Accepted Answer

A)     E4 	ext { E4 } E4  
B)  Sa
C)  SBb
D)  SBV
E)    B2 S\mathrm { B } 2 \mathrm {~S}B2 SF) B) and C)
G) A) and B)

Question 2

The type of radiation coming from active nuclei due to electrons spiraling in very strongmagnetic fields at relativistic speeds is:

Accepted Answer

A)  positron radiation.
B)  thermal energy.
C)  a blackbody curve.
D)  synchrotron radiation.
E)  nuclear energy.F) C) and E)
G) A) and D)

Question 3

In color photos, spirals typically have ________ arms with pink H II regions.

Accepted Answer

The answer of In color photos, spirals typically have ________...

Question 4

Almost all active galactic nuclei seem to be involved in ________ with neighbors.

Accepted Answer

The answer of Almost all active galactic nuclei seem to...

Question 5

How can the size of a quasar be measured?

Accepted Answer

The size of a quasar...

Question 6

Which statement about the Local Group is FALSE?

Accepted Answer

A)  It contains about 45 member galaxies.
B)  Its notable spirals include the Milky Way, M31, and M33.
C)  Most of its members are dwarf elliptical and irregular galaxies.
D)  It contains the large radio galaxy Centaurus A.
E)  It is about three million light-years across.F) C) and E)
G) A) and E)

Question 7

Type Sc are the dustiest of the galaxies.

Accepted Answer

A) True 
 B)False

Question 8

M-87, the giant elliptical at the heart of the Virgo Supercluster, shows a(n)________extending outward from its core, moving at relativistic velocities.

Accepted Answer

The answer of M-87, the giant elliptical at the heart...

Question 9

According to Hubble's Law, the greater a galaxy's redshift, the:

Accepted Answer

A)  closer it is to us.
B)  younger it is.
C)  faster it's approaching us.
D)  farther it is from us.
E)  greater its mass.F) A) and E)
G) B) and C)

Question 10

Why does the Cepheid "standard candle" have limited usefulness beyond 20 Mpc?

Accepted Answer

A)  Distant galaxies are seen in the past, when Cepheid variables behaved differently than they dotoday.
B)  Distant galaxies are so young they do not contain Cepheids.
C)  Cepheids are too faint to be seen beyond that distance, even with HST.
D)  The light variability of Cepheids diminishes with distance so they do not appear to vary there.
E)  Older distant Cepheids are of Population II, where the period-luminosity relation no longerworks.F) C) and D)
G) A) and B)

Question 11

In Hubble's classification, which type of galaxy has a small bulge and loose, widely spread,poorly defined spiral pattern?

Accepted Answer

A)  SO
B)  S9
C)  Sa
D)  Sc
E)  SBwF) A) and D)
G) C) and D)

Question 12

Astronomers observe unobscured X-rays generated in active galactic nuclei.

Accepted Answer

A) True 
 B)False

Question 13

Synchrotron radiation produces a(n) ________ spectrum.

Accepted Answer

A)  continuous nonthermal
B)  emission line
C)  absorption line
D)  continuous, with some emission lines
E)  continuous, with some absorption linesF) B) and D)
G) A) and E)

Question 14

An intermediately wound barred spiral galaxy would, in Hubble's system, be:

Accepted Answer

A)     BS2. 	ext { BS2. } BS2.  
B)     BSE.5. 	ext { BSE.5. } BSE.5.  
C)  SBb.
D)  S2B.
E)  SIrr. F) C) and D)
G) A) and E)

Question 15

Why is the energy source for active nuclei like Seyferts thought to be compact?

Accepted Answer

A)  The sources appear to be single stars in photos.
B)  Their energy appears to be non-stellar synchrotron radiation.
C)  The light can vary over short time intervals.
D)  We know the masses of the black holes that lurk there, and can find their radii.
E)  They are all strong radio sources, with assigned frequencies by their sizes.F) C) and E)
G) A) and B)

Question 16

The first hint that the universe might be expanding came from Vesto Slipher's work with thespectra of spiral nebulae in 1912.

Accepted Answer

A) True 
 B)False

Question 17

Why is it that the quasars we see represent a time when the universe was younger?

Accepted Answer

Quasars have very large redshi...

Question 18

Hubble's Law starts as a plot of recessional ________ versus distance to the galaxies.

Accepted Answer

The answer of Hubble's Law starts as a plot of...

Question 19

The magnetic fields carried by jets coming from active galactic nuclei are generated by:

Accepted Answer

A)  the combined magnetic fields of the many stars near the galaxy's center.
B)  the central black hole.
C)  the movement of the interstellar matter of the galaxy.
D)  the movement of the stars in the galaxy.
E)  charged matter in the accretion disk of the central black hole.F) All of the above
G) C) and D)

Question 20

The latest evidence from 2MASS suggests our own Milky Way is type SBb.

Accepted Answer

A) True 
 B)False

Exam 24: Galaxies: Building Blocks of the Universe

How can the size of a quasar be measured?

Correct AnswerverifiedThe size of a quasar...View AnswerShow Answer

Type Sc are the dustiest of the galaxies.

Correct AnswerverifiedShow Answer

In color photos, spirals typically have ________ arms with pink H II regions.

Correct AnswerverifiedShow Answer

Why does the Cepheid "standard candle" have limited usefulness beyond 20 Mpc?

Correct AnswerverifiedShow Answer

The first hint that the universe might be expanding came from Vesto Slipher's work with thespectra of spiral nebulae in 1912.

Correct AnswerverifiedShow Answer

In Hubble's classification, which type of galaxy has a small bulge and loose, widely spread,poorly defined spiral pattern?

Correct AnswerverifiedShow Answer

The magnetic fields carried by jets coming from active galactic nuclei are generated by:

Correct AnswerverifiedShow Answer

Why is it that the quasars we see represent a time when the universe was younger?

Correct AnswerverifiedQuasars have very large redshi...View AnswerShow Answer

Almost all active galactic nuclei seem to be involved in ________ with neighbors.

Correct AnswerverifiedShow Answer

Why is the energy source for active nuclei like Seyferts thought to be compact?

Correct AnswerverifiedShow Answer

An intermediately wound barred spiral galaxy would, in Hubble's system, be:

Correct AnswerverifiedShow Answer

The Milky Way is often considered to be an intermediately wound, barred spiral, whichwould be type ________ according to Hubble.

Correct AnswerverifiedShow Answer

Hubble's Law starts as a plot of recessional ________ versus distance to the galaxies.

Correct AnswerverifiedShow Answer

Synchrotron radiation produces a(n) ________ spectrum.

Correct AnswerverifiedShow Answer

Which statement about the Local Group is FALSE?

Correct AnswerverifiedShow Answer

According to Hubble's Law, the greater a galaxy's redshift, the:

Correct AnswerverifiedShow Answer

The latest evidence from 2MASS suggests our own Milky Way is type SBb.

Correct AnswerverifiedShow Answer

Astronomers observe unobscured X-rays generated in active galactic nuclei.

Correct AnswerverifiedShow Answer

The type of radiation coming from active nuclei due to electrons spiraling in very strongmagnetic fields at relativistic speeds is:

Correct AnswerverifiedShow Answer

M-87, the giant elliptical at the heart of the Virgo Supercluster, shows a(n)________extending outward from its core, moving at relativistic velocities.

Correct AnswerverifiedShow Answer

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The size of a quasar...
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Quasars have very large redshi...
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