Question 1

Which of the following is true about neutrinos?

Accepted Answer

A)  They are a possible example of cold dark matter. 
B)  They are a possible example of hot dark matter. 
C)  They have been theoretically predicted, yet never detected. 
D)  They must be much more massive than the dark matter candidate called photino. 
E)  They account for all the dark matter in the universe. 
A)  They are a possible example of cold dark matter. 
B)  They are a possible example of hot dark matter. 
C)  They have been theoretically predicted, yet never detected. 
D)  They must be much more massive than the dark matter candidate called photino. 
E)  They account for all the dark matter in the universe.

Question 2

According to the figure below, the maximum star formation rate in the past was about ________ the star formation rate today.

Accepted Answer

A)  the same as 
B)  5 times 
C)  20 times 
D)  100 times 
E)  10,000 times 
A)  the same as 
B)  5 times 
C)  20 times 
D)  100 times 
E)  10,000 times

Question 3

Which of these statements about galaxy clusters is true?

Accepted Answer

A)  Galaxy clusters do not require dark matter in order to form. 
B)  Galaxy clusters are the largest structures in the universe. 
C)  Small galaxy clusters form first and then merge to form larger galaxy clusters. 
D)  Galaxy clusters are evenly distributed throughout the universe. 
E)  There are such large distances between galaxy clusters that they never actually run into each other. 
A)  Galaxy clusters do not require dark matter in order to form. 
B)  Galaxy clusters are the largest structures in the universe. 
C)  Small galaxy clusters form first and then merge to form larger galaxy clusters. 
D)  Galaxy clusters are evenly distributed throughout the universe. 
E)  There are such large distances between galaxy clusters that they never actually run into each other.

Question 4

Structure in our universe evolved by initially forming

Accepted Answer

A)  giant galaxies, some of which later fragmented into dwarf galaxies. 
B)  dwarf galaxies that later merged to form bigger galaxies. 
C)  individual, free-floating stars, that later aggregated to form galaxies. 
D)  hot dark matter that later cooled into cold dark matter. 
E)  all types and sizes of galaxies at the same time. 
A)  giant galaxies, some of which later fragmented into dwarf galaxies. 
B)  dwarf galaxies that later merged to form bigger galaxies. 
C)  individual, free-floating stars, that later aggregated to form galaxies. 
D)  hot dark matter that later cooled into cold dark matter. 
E)  all types and sizes of galaxies at the same time.

Question 5

Scientists estimate that, in the distant cosmic future, before the universe becomes filled exclusively with elementary particles, the last large concentrations of mass will be

Accepted Answer

A)  white dwarfs. 
B)  neutron stars. 
C)  black holes. 
D)  brown dwarfs. 
E)  ultrafaint galaxies. 
A)  white dwarfs. 
B)  neutron stars. 
C)  black holes. 
D)  brown dwarfs. 
E)  ultrafaint galaxies.

Question 6

Based on the snapshot of a Bolshoi cosmological simulation in the figure below, roughly estimate the size of the largest void captured in the frame.Note that each side of the square field in the simulation represents 89 Mpc.

Accepted Answer

A fast visual estimate (white

Question 7

The diameter of the Local Group of galaxies is closest to which of the following distances?

Accepted Answer

A)  50 AU 
B)  100,000 light-years 
C)  3 million parsecs 
D)  200 million light-years 
E)  1 billion parsecs 
A)  50 AU 
B)  100,000 light-years 
C)  3 million parsecs 
D)  200 million light-years 
E)  1 billion parsecs

Question 8

Why can't dark matter halos collapse to be the same size as the visible parts of galaxies?

Accepted Answer

A)  Dark matter can't dissipate its energy through radiation from collisions. 
B)  Dark matter is made mostly of mini-black holes. 
C)  Dark matter has much more angular momentum. 
D)  Dark matter annihilates when it begins to get that dense. 
E)  Dark matter particles are too large to collapse that much. 
A)  Dark matter can't dissipate its energy through radiation from collisions. 
B)  Dark matter is made mostly of mini-black holes. 
C)  Dark matter has much more angular momentum. 
D)  Dark matter annihilates when it begins to get that dense. 
E)  Dark matter particles are too large to collapse that much.

Question 9

What is the fundamental difference between the two "temperatures" of dark matter candidates? List an example of each type.

Accepted Answer

Cold dark matter particles move relative

Question 10

How do the properties of the CMB give support to the existence of dark matter?

Accepted Answer

A)  The CMB has the same temperature as the cold dark matter. 
B)  The faint glow of the CMB was actually produced by dark matter particles as they annihilated particles of normal matter. 
C)  The opaque CMB is essentially hiding the dark matter that existed earlier in the universe. 
D)  The CMB is too smooth to account for the structure we observe in the universe unless dark matter exists. 
E)  The observed spatial scale of CMB clumping perfectly matches that of the dark matter. 
A)  The CMB has the same temperature as the cold dark matter. 
B)  The faint glow of the CMB was actually produced by dark matter particles as they annihilated particles of normal matter. 
C)  The opaque CMB is essentially hiding the dark matter that existed earlier in the universe. 
D)  The CMB is too smooth to account for the structure we observe in the universe unless dark matter exists. 
E)  The observed spatial scale of CMB clumping perfectly matches that of the dark matter.

Question 11

By measuring the star formation rate in galaxies as a function of their redshift, we have learned that the average star formation rate in galaxies peaked approximately ________ years ago.

Accepted Answer

A)  1 billion 
B)  3 billion 
C)  5 billion 
D)  7 billion 
E)  11 billion 
A)  1 billion 
B)  3 billion 
C)  5 billion 
D)  7 billion 
E)  11 billion

Question 12

Neutrinos can be considered a form of dark matter.Describe what properties make neutrinos suitable dark matter candidates, and explain whether they can be considered hot or cold dark matter.

Accepted Answer

Neutrinos belong to the so-called hot da

Question 13

The figure below shows snapshots taken from the Bolshoi simulation of the formation of the large-scale structure in the universe.Which one of these images represents the state of the universe at the highest redshift?

Accepted Answer

A)  A 
B)  B 
C)  C 
D)  D 
E)  All of these occur at the same redshift, just in different regions of the universe. 
A)  A 
B)  B 
C)  C 
D)  D 
E)  All of these occur at the same redshift, just in different regions of the universe.

Question 14

Out of all the mass and energy in the universe, ordinary matter (the stuff that makes up stars and gas, and all the things we interact with in everyday life) constitutes about

Accepted Answer

A)  4-5 percent. 
B)  10 percent. 
C)  half. 
D)  85 percent. 
E)  99 percent. 
A)  4-5 percent. 
B)  10 percent. 
C)  half. 
D)  85 percent. 
E)  99 percent.

Question 15

Filaments and voids are hallmarks of

Accepted Answer

A)  reionization. 
B)  large-scale structure. 
C)  spiral galaxies. 
D)  elementary particles. 
E)  hot dark matter. 
A)  reionization. 
B)  large-scale structure. 
C)  spiral galaxies. 
D)  elementary particles. 
E)  hot dark matter.

Question 16

Which of the following best explains the difference between the heavy-element abundances seen in the first stars and those seen in stars that we observe today?

Accepted Answer

A)  Stars today have more heavy elements because modern stars have higher masses, allowing them to create more heavy elements through nuclear fusion. 
B)  Stars today have more heavy elements because the gas that formed the current stars was enriched by the higher-mass elements formed in previous generations of stars. 
C)  Stars today have fewer heavy elements because they have been around long enough to use up the larger atoms. 
D)  Stars today have a smaller abundance of heavy elements because they haven't been around long enough to make as many of the larger atoms. 
E)  The stars that astronomers observe now are the first generation of stars. 
A)  Stars today have more heavy elements because modern stars have higher masses, allowing them to create more heavy elements through nuclear fusion. 
B)  Stars today have more heavy elements because the gas that formed the current stars was enriched by the higher-mass elements formed in previous generations of stars. 
C)  Stars today have fewer heavy elements because they have been around long enough to use up the larger atoms. 
D)  Stars today have a smaller abundance of heavy elements because they haven't been around long enough to make as many of the larger atoms. 
E)  The stars that astronomers observe now are the first generation of stars.

Question 17

Dark matter constitutes ________ of the mass in galaxy clusters, while the majority of non-dark matter mass is found in ________.

Accepted Answer

A)  the majority; supermassive black holes 
B)  a minority; supermassive black holes 
C)  a minority; cold gas 
D)  the majority; hot gas 
E)  none; old stars 
A)  the majority; supermassive black holes 
B)  a minority; supermassive black holes 
C)  a minority; cold gas 
D)  the majority; hot gas 
E)  none; old stars

Question 18

What stage in the evolution of the universe is coined "the epoch of reionization," and what is the significance of this name?

Accepted Answer

The epoch of reionization signifies the

Question 19

Explain how computer simulations of structure formation and observations of the structure in the universe can help astronomers determine the nature of dark matter.

Accepted Answer

Only simulations with specific types and

Question 20

Which of these is the correct order of collections of galaxies, from smallest to largest?

Accepted Answer

A)  group, supercluster, cluster 
B)  cluster, supercluster, group 
C)  group, cluster, supercluster 
D)  cluster, group, supercluster 
E)  supercluster, group, cluster 
A)  group, supercluster, cluster 
B)  cluster, supercluster, group 
C)  group, cluster, supercluster 
D)  cluster, group, supercluster 
E)  supercluster, group, cluster

Exam 23: Large-Scale Structure in the Universe

Which of the following is true about neutrinos?

According to the figure below, the maximum star formation rate in the past was about ________ the star formation rate today.

Which of these statements about galaxy clusters is true?

Structure in our universe evolved by initially forming

Scientists estimate that, in the distant cosmic future, before the universe becomes filled exclusively with elementary particles, the last large concentrations of mass will be

Based on the snapshot of a Bolshoi cosmological simulation in the figure below, roughly estimate the size of the largest void captured in the frame.Note that each side of the square field in the simulation represents 89 Mpc.

The diameter of the Local Group of galaxies is closest to which of the following distances?

Why can't dark matter halos collapse to be the same size as the visible parts of galaxies?

What is the fundamental difference between the two "temperatures" of dark matter candidates? List an example of each type.

How do the properties of the CMB give support to the existence of dark matter?

By measuring the star formation rate in galaxies as a function of their redshift, we have learned that the average star formation rate in galaxies peaked approximately ________ years ago.

Neutrinos can be considered a form of dark matter.Describe what properties make neutrinos suitable dark matter candidates, and explain whether they can be considered hot or cold dark matter.

The figure below shows snapshots taken from the Bolshoi simulation of the formation of the large-scale structure in the universe.Which one of these images represents the state of the universe at the highest redshift?

Out of all the mass and energy in the universe, ordinary matter (the stuff that makes up stars and gas, and all the things we interact with in everyday life) constitutes about

Filaments and voids are hallmarks of

Which of the following best explains the difference between the heavy-element abundances seen in the first stars and those seen in stars that we observe today?

Dark matter constitutes ________ of the mass in galaxy clusters, while the majority of non-dark matter mass is found in ________.

What stage in the evolution of the universe is coined "the epoch of reionization," and what is the significance of this name?

Explain how computer simulations of structure formation and observations of the structure in the universe can help astronomers determine the nature of dark matter.

Which of these is the correct order of collections of galaxies, from smallest to largest?

Thinking Like an Astronomer

Patterns in the Skymotions of Earth and the Moon

Motion of Astronomical Bodies

Gravity and Orbits

Light

The Tools of the Astronomer

The Formation of Planetary Systems

The Terrestrial Planets and Earths Moon

Atmospheres of the Terrestrial Planets

Worlds of Gas and Liquidthe Giant Planets

Planetary Moons and Rings

Dwarf Planets and Small Solar System Bodies

Taking the Measure of Stars

Our Starthe Sun

The Interstellar Medium and Star Formation

Evolution of Low-Mass Stars

Evolution of High-Mass Stars

Relativity and Black Holes

Galaxies

The Milky Waya Normal Spiral Galaxy

The Expanding Universe

Cosmology

Life

Filters

Dark matter constitutes of the mass in galaxy clusters, while the majority of non-dark matter mass is found in .