Question 1

How can the velocity dispersion and radius of an elliptical galaxy determine its mass?

Accepted Answer

The velocity dispersion depends upon the escape speed,which is proportional to the square root of mass divided by radius.

Question 2

Which astronomer discovered dark matter in spiral galaxies?

Accepted Answer

A)  Harlow Shapley 
B)  Edwin Hubble 
C)  Arno Penzias 
D)  Vera Rubin 
A)  Harlow Shapley 
B)  Edwin Hubble 
C)  Arno Penzias 
D)  Vera Rubin D

Question 3

The figure below shows three spiral galaxies.Classify them as Sa,Sb,and Sc galaxies.There is one of each type of galaxy in the figure.

Accepted Answer

A is an Sb galaxy,B is an Sa galaxy,and C is an Sc galaxy.

Question 4

What does the M-sigma relation demonstrate about black holes?

Accepted Answer

A)  They result from massive stars' deaths. 
B)  That black holes and galaxies grow together. 
C)  They grow primarily through accretion. 
D)  That black holes form the majority of mass within galactic bulges. 
A)  They result from massive stars' deaths. 
B)  That black holes and galaxies grow together. 
C)  They grow primarily through accretion. 
D)  That black holes form the majority of mass within galactic bulges.

Question 5

Because of an obscuring atmosphere,an observer in a distant galaxy can only see the nearest 1,000 stars to his or her home planet.How could the observer most directly determine that he or she lives inside an elliptical galaxy?

Accepted Answer

A)  by measuring the brightnesses of the stars 
B)  by mapping the locations of the stars on the sky 
C)  by measuring the differences in velocities between the stars 
D)  by measuring the masses of the stars 
A)  by measuring the brightnesses of the stars 
B)  by mapping the locations of the stars on the sky 
C)  by measuring the differences in velocities between the stars 
D)  by measuring the masses of the stars

Question 6

An astronomer discovers a knot of emission that appears to escape a radio galaxy at three times the speed of light.What makes this phenomenon possible?

Accepted Answer

A)  The central black hole produces an exotic particle that travels faster than the speed of light. 
B)  Magnetic fields accelerate the jet particles. 
C)  Nothing; it is an optical illusion. 
D)  Nothing; it is a consequence of the cosmological expansion. 
A)  The central black hole produces an exotic particle that travels faster than the speed of light. 
B)  Magnetic fields accelerate the jet particles. 
C)  Nothing; it is an optical illusion. 
D)  Nothing; it is a consequence of the cosmological expansion.

Question 7

In the early 20th century,some astronomers incorrectly believed that they could observe features in spiral nebulae rotate over the course of a few years.If those observations were correct,what would they have immediately suggested about the nature of these nebulae?

Accepted Answer

A)  that they were island universes 
B)  that they were inside the Milky Way 
C)  that they were forming stars 
D)  that they were accretion disks 
A)  that they were island universes 
B)  that they were inside the Milky Way 
C)  that they were forming stars 
D)  that they were accretion disks

Question 8

Why is rapid variability (over the course of weeks)a strong argument that quasars are powered by supermassive black holes?

Accepted Answer

A)  Variability shows that black holes grow rapidly. 
B)  Variability shows that black holes are unstable. 
C)  Variability allows astronomers to estimate the size of the emitting region. 
D)  Variability rules out accretion disks as the source. 
A)  Variability shows that black holes grow rapidly. 
B)  Variability shows that black holes are unstable. 
C)  Variability allows astronomers to estimate the size of the emitting region. 
D)  Variability rules out accretion disks as the source.

Question 9

Name three aspects of elliptical galaxies that point toward their origin in collisions between galaxies.

Accepted Answer

They are more massive (on aver

Question 10

Two elliptical galaxies have identical radii and luminosities,but stars in galaxy A have a maximum orbital speed three times that of galaxy B.How much more massive is galaxy A than galaxy B?

Accepted Answer

A)  nine times more 
B)  three times more 
C)  1.7 times more 
D)  1.3 times more 
A)  nine times more 
B)  three times more 
C)  1.7 times more 
D)  1.3 times more

Question 11

Which astronomer definitively established the existence of galaxies outside the Milky Way?

Accepted Answer

A)  Galileo 
B)  William Herschel 
C)  Harlow Shapley 
D)  Edwin Hubble 
A)  Galileo 
B)  William Herschel 
C)  Harlow Shapley 
D)  Edwin Hubble

Question 12

An elliptical galaxy has:

Accepted Answer

A)  blue stars and plunging orbits. 
B)  red stars and lots of gas and dust. 
C)  red stars and plunging orbits. 
D)  blue stars and lots of gas and dust. 
A)  blue stars and plunging orbits. 
B)  red stars and lots of gas and dust. 
C)  red stars and plunging orbits. 
D)  blue stars and lots of gas and dust.

Question 13

An astronomer discovers an unusual active galactic nucleus without any orbiting clouds.How would such a source differ from a typical quasar?

Accepted Answer

A)  It would lack emission lines. 
B)  It would lack a jet. 
C)  It would not have variability. 
D)  all of the above 
A)  It would lack emission lines. 
B)  It would lack a jet. 
C)  It would not have variability. 
D)  all of the above

Question 14

Why were Cepheid variables essential to the discovery of galaxies outside the Milky Way?

Accepted Answer

They are standard candles by w

Question 15

The figure below is an illustration of what astronomical relation?

Accepted Answer

A)  Wien's law 
B)  the Tully-Fisher relation 
C)  Hubble's law 
D)  the inverse-square law 
A)  Wien's law 
B)  the Tully-Fisher relation 
C)  Hubble's law 
D)  the inverse-square law

Question 16

A spiral galaxy is observed to have undergone a recent episode of intense star formation near its center.Which of the following is this galaxy most likely to have had in its recent past?

Accepted Answer

A)  a flocculent phase 
B)  a grand design phase 
C)  globular clusters 
D)  a bar 
A)  a flocculent phase 
B)  a grand design phase 
C)  globular clusters 
D)  a bar

Question 17

Which of the following lists astronomical distance measurement techniques in order of the maximum distance to which they are useful?

Accepted Answer

A)  parallax, spectroscopic parallax, Hubble's law, Type Ia supernova 
B)  parallax, Cepheid variables, spectroscopic parallax, Hubble's law 
C)  parallax, Cepheid variables, Type Ia supernova, the Tully-Fisher law, Hubble's law 
D)  parallax, Cepheid variables, Type Ia supernova, Hubble's law 
A)  parallax, spectroscopic parallax, Hubble's law, Type Ia supernova 
B)  parallax, Cepheid variables, spectroscopic parallax, Hubble's law 
C)  parallax, Cepheid variables, Type Ia supernova, the Tully-Fisher law, Hubble's law 
D)  parallax, Cepheid variables, Type Ia supernova, Hubble's law

Question 18

Why are the bars in barred spiral galaxies typically bright?

Accepted Answer

They conta

Question 19

What are the four major classes of galaxies in the Universe?

Accepted Answer

Spirals,barred spira

Question 20

Which of the following is NOT a component of the unified model of active galactic nuclei?

Accepted Answer

A)  a corona 
B)  a jet 
C)  a torus 
D)  an accretion disk 
A)  a corona 
B)  a jet 
C)  a torus 
D)  an accretion disk

How can the velocity dispersion and radius of an elliptical galaxy determine its mass?

Which astronomer discovered dark matter in spiral galaxies?

The figure below shows three spiral galaxies.Classify them as Sa,Sb,and Sc galaxies.There is one of each type of galaxy in the figure.

What does the M-sigma relation demonstrate about black holes?

Because of an obscuring atmosphere,an observer in a distant galaxy can only see the nearest 1,000 stars to his or her home planet.How could the observer most directly determine that he or she lives inside an elliptical galaxy?

An astronomer discovers a knot of emission that appears to escape a radio galaxy at three times the speed of light.What makes this phenomenon possible?

In the early 20th century,some astronomers incorrectly believed that they could observe features in spiral nebulae rotate over the course of a few years.If those observations were correct,what would they have immediately suggested about the nature of these nebulae?

Why is rapid variability (over the course of weeks)a strong argument that quasars are powered by supermassive black holes?

Name three aspects of elliptical galaxies that point toward their origin in collisions between galaxies.

Two elliptical galaxies have identical radii and luminosities,but stars in galaxy A have a maximum orbital speed three times that of galaxy B.How much more massive is galaxy A than galaxy B?

Which astronomer definitively established the existence of galaxies outside the Milky Way?

An elliptical galaxy has:

An astronomer discovers an unusual active galactic nucleus without any orbiting clouds.How would such a source differ from a typical quasar?

Why were Cepheid variables essential to the discovery of galaxies outside the Milky Way?

The figure below is an illustration of what astronomical relation?

A spiral galaxy is observed to have undergone a recent episode of intense star formation near its center.Which of the following is this galaxy most likely to have had in its recent past?

Which of the following lists astronomical distance measurement techniques in order of the maximum distance to which they are useful?

Why are the bars in barred spiral galaxies typically bright?

What are the four major classes of galaxies in the Universe?

Which of the following is NOT a component of the unified model of active galactic nuclei?

Getting Started: Science, astronomy, and Being Human

A Universe Made, a Universe Discovered

A Universe of Universal Laws

A Universe of Universal Laws

The Architecture and Birth of Planetary Systems

Home Base: Earth and Moon

Sibling Worlds: Mercury, Venus, and Mars

Gas, ice, and Stone: the Outer Planets

Life and the Search for Habitable Worlds

The Sun As a Star

Measuring the Stars: the Main Sequence and Its Meaning

Nursery of the Stars: the Interstellar Medium and Star Formation

To the Graveyard of Stars: the End Points of Stellar Evolution

Down the Rabbit Hole: Relativity and Black Holes

Our City of Stars: the Milky Way

The Cosmic Web: the Large-Scale Structure of the Universe

Cosmology

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Exam 16: A Universe of Galaxies

How can the velocity dispersion and radius of an elliptical galaxy determine its mass?

Which astronomer discovered dark matter in spiral galaxies?

The figure below shows three spiral galaxies.Classify them as Sa,Sb,and Sc galaxies.There is one of each type of galaxy in the figure.

What does the M-sigma relation demonstrate about black holes?

Because of an obscuring atmosphere,an observer in a distant galaxy can only see the nearest 1,000 stars to his or her home planet.How could the observer most directly determine that he or she lives inside an elliptical galaxy?

An astronomer discovers a knot of emission that appears to escape a radio galaxy at three times the speed of light.What makes this phenomenon possible?

In the early 20th century,some astronomers incorrectly believed that they could observe features in spiral nebulae rotate over the course of a few years.If those observations were correct,what would they have immediately suggested about the nature of these nebulae?

Why is rapid variability (over the course of weeks)a strong argument that quasars are powered by supermassive black holes?

Name three aspects of elliptical galaxies that point toward their origin in collisions between galaxies.

Two elliptical galaxies have identical radii and luminosities,but stars in galaxy A have a maximum orbital speed three times that of galaxy B.How much more massive is galaxy A than galaxy B?

Which astronomer definitively established the existence of galaxies outside the Milky Way?

An elliptical galaxy has:

An astronomer discovers an unusual active galactic nucleus without any orbiting clouds.How would such a source differ from a typical quasar?

Why were Cepheid variables essential to the discovery of galaxies outside the Milky Way?

The figure below is an illustration of what astronomical relation?

A spiral galaxy is observed to have undergone a recent episode of intense star formation near its center.Which of the following is this galaxy most likely to have had in its recent past?

Which of the following lists astronomical distance measurement techniques in order of the maximum distance to which they are useful?

Why are the bars in barred spiral galaxies typically bright?

What are the four major classes of galaxies in the Universe?

Which of the following is NOT a component of the unified model of active galactic nuclei?

Getting Started: Science, astronomy, and Being Human

A Universe Made, a Universe Discovered

A Universe of Universal Laws

A Universe of Universal Laws

The Architecture and Birth of Planetary Systems

Home Base: Earth and Moon

Sibling Worlds: Mercury, Venus, and Mars

Gas, ice, and Stone: the Outer Planets

Life and the Search for Habitable Worlds

The Sun As a Star

Measuring the Stars: the Main Sequence and Its Meaning

Nursery of the Stars: the Interstellar Medium and Star Formation

To the Graveyard of Stars: the End Points of Stellar Evolution

Down the Rabbit Hole: Relativity and Black Holes

Our City of Stars: the Milky Way

The Cosmic Web: the Large-Scale Structure of the Universe

Cosmology

Filters