Question 1

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 2

The "Lambda-CDM" model combines the properties of __________ to explain the formation of structure in the universe.

Accepted Answer

A) black holes and neutron stars 
B) dark energy and cold dark matter 
C) star formation and angular momentum 
D) nucleosynthesis and hot dark matter 
E) gravity and nuclear forces 
A) black holes and neutron stars 
B) dark energy and cold dark matter 
C) star formation and angular momentum 
D) nucleosynthesis and hot dark matter 
E) gravity and nuclear forces

Question 3

Describe the large-scale structure of the universe.

Accepted Answer

The structure of the universe

Question 4

What does the large-scale structure of the universe look most like?

Accepted Answer

A) a sponge with many large holes 
B) a loaf of wheat bread with many tiny holes 
C) a plate of flat noodles 
D) a jar of marbles 
E) a pizza with evenly spread out pepperoni 
A) a sponge with many large holes 
B) a loaf of wheat bread with many tiny holes 
C) a plate of flat noodles 
D) a jar of marbles 
E) a pizza with evenly spread out pepperoni

Question 5

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,then merge together 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,then merge together 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 6

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) 12 billion 
A) 1 billion 
B) 3 billion 
C) 5 billion 
D) 7 billion 
E) 12 billion

Question 7

The peculiar velocities of galaxies allow us to determine how matter is distributed in the universe.

Accepted Answer

A) True 
 B)False

Question 8

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 9

What is the fundamental difference between the two basic types of dark matter? List an example of each type.

Accepted Answer

Cold dark matter particles are heavy and

Question 10

Peculiar velocities are produced by:

Accepted Answer

A) erroneous redshifts 
B) gravity 
C) supernovae 
D) eclipsing binary stars 
E) interstellar winds 
A) erroneous redshifts 
B) gravity 
C) supernovae 
D) eclipsing binary stars 
E) interstellar winds

Question 11

Which of the following best explain 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 that were formed in the first stars. 
C) Stars today have a fewer heavy elements,because they have been around long enough to use up the larger mass 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 that were formed in the first stars. 
C) Stars today have a fewer heavy elements,because they have been around long enough to use up the larger mass 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 12

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 13

Which is NOT an ingredient needed to build a cosmological simulation of large-scale structure formation?

Accepted Answer

A) the spectrum of density fluctuations that quantum mechanics imprints on the early universe 
B) the density of dark matter and luminous matter in the universe 
C) the grand unified theory 
D) the density of dark energy in the universe 
E) None of the above;all of the above are necessary. 
A) the spectrum of density fluctuations that quantum mechanics imprints on the early universe 
B) the density of dark matter and luminous matter in the universe 
C) the grand unified theory 
D) the density of dark energy in the universe 
E) None of the above;all of the above are necessary.

Question 14

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

Accepted Answer

Only simulations with specific types and

Question 15

In the early universe,why were inhomogeneities in the distribution of normal matter much smaller than the inhomogeneities in the dark matter?

Accepted Answer

A) Normal matter is pushed away by supernova explosions. 
B) Magnetic fields smoothed the distribution of charged particles in the normal matter but not in dark matter. 
C) Dark matter particles were more massive and cooled off before normal matter,thus dark matter fluctuations had a longer time over which to grow. 
D) Dark matter was 10 times more massive than normal matter. 
E) Radiation pressure affected normal matter but not dark matter. 
A) Normal matter is pushed away by supernova explosions. 
B) Magnetic fields smoothed the distribution of charged particles in the normal matter but not in dark matter. 
C) Dark matter particles were more massive and cooled off before normal matter,thus dark matter fluctuations had a longer time over which to grow. 
D) Dark matter was 10 times more massive than normal matter. 
E) Radiation pressure affected normal matter but not dark matter.

Question 16

How do we know how fast the Milky Way is moving relative to the local universe? What are we moving toward,and what do we think is mostly responsible for this motion?

Accepted Answer

The Doppler shift of the CMB tells us ho

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)states that,due

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

As structure formed in the universe,galaxy-sized objects formed before cluster-sized objects.

Accepted Answer

A) True 
 B)False

Question 20

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.

Exam 23: Large-Scale Structure in the Universe

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

The "Lambda-CDM" model combines the properties of __________ to explain the formation of structure in the universe.

Describe the large-scale structure of the universe.

What does the large-scale structure of the universe look most like?

Which of these statements about galaxy clusters is true?

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.

The peculiar velocities of galaxies allow us to determine how matter is distributed in the universe.

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:

What is the fundamental difference between the two basic types of dark matter? List an example of each type.

Peculiar velocities are produced by:

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

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

Which is NOT an ingredient needed to build a cosmological simulation of large-scale structure formation?

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

In the early universe,why were inhomogeneities in the distribution of normal matter much smaller than the inhomogeneities in the dark matter?

How do we know how fast the Milky Way is moving relative to the local universe? What are we moving toward,and what do we think is mostly responsible for this motion?

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:

As structure formed in the universe,galaxy-sized objects formed before cluster-sized objects.

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

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 Adornments Moons 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