Question 1

In clusters of galaxies, the total mass of dark matter exceeds the luminous matter by about a factor of 1,000.

Accepted Answer

A) True 
 B)False

Question 2

Describe the large-scale structure of the universe.

Accepted Answer

The structure of the universe

Question 3

Why do astronomers think that cold dark matter (as opposed to hot dark matter) is the primary component of dark matter in galaxies?

Accepted Answer

Because cold dark matter can condense ar

Question 4

We expect the kinds of galaxies that we see at a redshift of z = 4 to be:

Accepted Answer

A)  much like what we see today 
B)  smaller and much more irregular looking than today 
C)  smaller versions of what we see today 
D)  far more numerous but with fewer spiral galaxies 
E)  larger versions of what we see today 
A)  much like what we see today 
B)  smaller and much more irregular looking than today 
C)  smaller versions of what we see today 
D)  far more numerous but with fewer spiral galaxies 
E)  larger versions of what we see today

Question 5

Which of the following statements about the Dark Ages of the universe is FALSE?

Accepted Answer

A)  The first stars began forming during the Dark Ages. 
B)  The end of the Dark Ages coincided with reionization. 
C)  The Dark Ages lasted from 200 to 600 million years after the Big Bang. 
D)  During the Dark Ages, photons could travel freely through the universe. 
E)  Recombination occurred before the Dark Ages. 
A)  The first stars began forming during the Dark Ages. 
B)  The end of the Dark Ages coincided with reionization. 
C)  The Dark Ages lasted from 200 to 600 million years after the Big Bang. 
D)  During the Dark Ages, photons could travel freely through the universe. 
E)  Recombination occurred before the Dark Ages.

Question 6

Compared to what we see today, galaxies in the past are:

Accepted Answer

A)  more ordered and more likely to have spiral structure 
B)  more ordered and less likely to have spiral structure 
C)  messier and more likely to have spiral structure 
D)  messier and less likely to have spiral structure 
E)  exactly the same as they are today 
A)  more ordered and more likely to have spiral structure 
B)  more ordered and less likely to have spiral structure 
C)  messier and more likely to have spiral structure 
D)  messier and less likely to have spiral structure 
E)  exactly the same as they are today

Question 7

Reionization of the neutral gas in the universe occurred due to the:

Accepted Answer

A)  decay of dark matter particles 
B)  emission of neutrinos by the first stars that formed 
C)  release of jets of charged particles from supermassive black holes 
D)  radiation from the first stars, supernovae, and black holes that formed 
E)  positron and electron annihilations 
A)  decay of dark matter particles 
B)  emission of neutrinos by the first stars that formed 
C)  release of jets of charged particles from supermassive black holes 
D)  radiation from the first stars, supernovae, and black holes that formed 
E)  positron and electron annihilations

Question 8

Put the following eras in the history of the evolution of the universe in their proper order from the earliest to the latest: black hole era, dark era, degenerate era, primordial era, and stelliferous era.

Accepted Answer

From first to last a

Question 9

Structure formation in our universe:

Accepted Answer

A)  occurs for the largest structures first 
B)  occurs for the smallest structures first 
C)  begins on all spatial scales at the same time 
D)  begins after clusters form 
E)  begins with planets 
A)  occurs for the largest structures first 
B)  occurs for the smallest structures first 
C)  begins on all spatial scales at the same time 
D)  begins after clusters form 
E)  begins with planets

Question 10

The first stars formed in the universe had __________ compared to the stars formed today.

Accepted Answer

A)  higher metallicity and higher mass 
B)  higher metallicity and lower mass 
C)  lower metallicity and higher mass 
D)  lower metallicity and lower mass 
E)  higher mass and longer lifetimes 
A)  higher metallicity and higher mass 
B)  higher metallicity and lower mass 
C)  lower metallicity and higher mass 
D)  lower metallicity and lower mass 
E)  higher mass and longer lifetimes

Question 11

Each of these statements describes the steps that occur during star formation. Which of these is NOT also true for galaxy formation?

Accepted Answer

A)  Angular momentum leads to the formation of a disk. 
B)  For both stars and galaxies, the largest objects form first, with smaller objects coming together later. 
C)  A gas cloud radiates energy, allowing it to collapse further than when it was hotter. 
D)  Gravitational instability leads to collapse. 
E)  The original large gas cloud splits into smaller fragments because areas with higher density also have greater gravitational pull. 
A)  Angular momentum leads to the formation of a disk. 
B)  For both stars and galaxies, the largest objects form first, with smaller objects coming together later. 
C)  A gas cloud radiates energy, allowing it to collapse further than when it was hotter. 
D)  Gravitational instability leads to collapse. 
E)  The original large gas cloud splits into smaller fragments because areas with higher density also have greater gravitational pull.

Question 12

If the quantum fluctuations imprinted on the dark matter halos at the time of the formation of the CMB were ten times larger and the Hubble Constant was the same as it is now, galaxies would likely be:

Accepted Answer

A)  smaller than they are now 
B)  larger than they are now 
C)  more numerous than they are now 
D)  nonexistent 
E)  exactly the same as they are now 
A)  smaller than they are now 
B)  larger than they are now 
C)  more numerous than they are now 
D)  nonexistent 
E)  exactly the same as they are now

Question 13

The first stars formed in the universe did not require the effects of dark matter to form.

Accepted Answer

A) True 
 B)False

Question 14

What process is most responsible for shaping the large-scale structure of the universe?

Accepted Answer

A)  supernovae from the first generation of stars 
B)  gravity 
C)  matter/antimatter annihilation 
D)  magnetic fields 
E)  electric force 
A)  supernovae from the first generation of stars 
B)  gravity 
C)  matter/antimatter annihilation 
D)  magnetic fields 
E)  electric force

Question 15

Which of the following is NOT a possible candidate for dark matter?

Accepted Answer

A)  axions 
B)  positrons 
C)  photinos 
D)  neutrinos 
E)  None of the above; all of these could be dark matter. 
A)  axions 
B)  positrons 
C)  photinos 
D)  neutrinos 
E)  None of the above; all of these could be dark matter.

Question 16

Which of the following is NOT likely to happen when two spiral galaxies collide?

Accepted Answer

A)  A more massive elliptical galaxy might form out of the merger. 
B)  The two supermassive black holes at their centers could form a binary black hole system. 
C)  Individual stars collide to create many supernovae. 
D)  A burst of star formation will occur in the merged galaxy. 
E)  The cold gas in the merged galaxy might be blown away by supernovae. 
A)  A more massive elliptical galaxy might form out of the merger. 
B)  The two supermassive black holes at their centers could form a binary black hole system. 
C)  Individual stars collide to create many supernovae. 
D)  A burst of star formation will occur in the merged galaxy. 
E)  The cold gas in the merged galaxy might be blown away by supernovae.

Question 17

Use Hubble's Law to explain how measurements of redshift help astronomers map out the large-scale structure of the universe.

Accepted Answer

Hubble's law (v = H₀ / D) sta

Question 18

Our current ideas on galaxy formation suggest that the visible parts of galaxies:

Accepted Answer

A)  form first and are incorporated into dark matter halos later 
B)  form only in the densest parts of dark matter halos 
C)  can tell you the total size of the dark matter halo 
D)  can tell you everything about the formation history of that galaxy 
E)  spread out over larger distances than dark matter halos 
A)  form first and are incorporated into dark matter halos later 
B)  form only in the densest parts of dark matter halos 
C)  can tell you the total size of the dark matter halo 
D)  can tell you everything about the formation history of that galaxy 
E)  spread out over larger distances than dark matter halos

Question 19

Which of the following is NOT a way in which astronomers detect dark matter in clusters of galaxies?

Accepted Answer

A)  by determining the amount of mass necessary to gravitationally collapse clouds of gas to form the number of stars present 
B)  by determining the amount of mass necessary to gravitationally hold onto the hot gas surrounding galaxy clusters 
C)  by determining the amount of mass necessary to gravitationally hold a cluster of galaxies together 
D)  by determining the amount of mass necessary to gravitationally lens images of distant objects 
E)  None of the above; all of these are ways that astronomers detect dark matter in galaxy clusters. 
A)  by determining the amount of mass necessary to gravitationally collapse clouds of gas to form the number of stars present 
B)  by determining the amount of mass necessary to gravitationally hold onto the hot gas surrounding galaxy clusters 
C)  by determining the amount of mass necessary to gravitationally hold a cluster of galaxies together 
D)  by determining the amount of mass necessary to gravitationally lens images of distant objects 
E)  None of the above; all of these are ways that astronomers detect dark matter in galaxy clusters.

Question 20

The most common type of galaxy found in a galaxy cluster is a ________ galaxy.

Accepted Answer

A)  spiral 
B)  giant elliptical 
C)  giant irregular 
D)  dwarf 
E)  barred spiral 
A)  spiral 
B)  giant elliptical 
C)  giant irregular 
D)  dwarf 
E)  barred spiral

Exam 23: Large-Scale Structure in the Universe

In clusters of galaxies, the total mass of dark matter exceeds the luminous matter by about a factor of 1,000.

Describe the large-scale structure of the universe.

Why do astronomers think that cold dark matter (as opposed to hot dark matter) is the primary component of dark matter in galaxies?

We expect the kinds of galaxies that we see at a redshift of z = 4 to be:

Which of the following statements about the Dark Ages of the universe is FALSE?

Compared to what we see today, galaxies in the past are:

Reionization of the neutral gas in the universe occurred due to the:

Put the following eras in the history of the evolution of the universe in their proper order from the earliest to the latest: black hole era, dark era, degenerate era, primordial era, and stelliferous era.

Structure formation in our universe:

The first stars formed in the universe had __________ compared to the stars formed today.

Each of these statements describes the steps that occur during star formation. Which of these is NOT also true for galaxy formation?

If the quantum fluctuations imprinted on the dark matter halos at the time of the formation of the CMB were ten times larger and the Hubble Constant was the same as it is now, galaxies would likely be:

The first stars formed in the universe did not require the effects of dark matter to form.

What process is most responsible for shaping the large-scale structure of the universe?

Which of the following is NOT a possible candidate for dark matter?

Which of the following is NOT likely to happen when two spiral galaxies collide?

Use Hubble's Law to explain how measurements of redshift help astronomers map out the large-scale structure of the universe.

Our current ideas on galaxy formation suggest that the visible parts of galaxies:

Which of the following is NOT a way in which astronomers detect dark matter in clusters of galaxies?

The most common type of galaxy found in a galaxy cluster is a ________ galaxy.

Why Learn Astronomy

Patterns in the Skymotions of Earth

Motion of Astronomical Bodies

Gravity and Orbits

Light

The Tools of the Astronomer

The Birth and Evolution of Planetary Systems

The Terrestrial Planets and Earths Moon

Atmospheres of the Terrestrial Planets

Worlds of Gas and Liquid the Giant Planets

Planetary Adornmentsmoons and Rings

Dwarf Planets and Small Solar System Bodies

Taking the Measure of Stars

Our Starthe Sun

Star Formation and the Interstellar Medium

Evolution of Low-Mass Stars

Evolution of High-Mass Stars

Relativity and Black Holes

The Expanding Universe

Galaxies

The Milky Waya Normal Spiral Galaxy

Modern Cosmology

Life

Filters