Question 1

How do astronomers know that dark matter is "cold"?

Accepted Answer

A)  laboratory measurements of its properties 
B)  computer simulations of structure formation 
C)  measurements of its annihilation radiation 
D)  gravitational lensing 
A)  laboratory measurements of its properties 
B)  computer simulations of structure formation 
C)  measurements of its annihilation radiation 
D)  gravitational lensing B

Question 2

Which of the following describes a void?

Accepted Answer

A)  a gap between spiral arms in a spiral galaxy 
B)  a gap in a protoplanetary disk 
C)  a region of the interstellar medium cleared of material by supernovas 
D)  a region 10-100 Mpc across where the galaxy density is very low 
A)  a gap between spiral arms in a spiral galaxy 
B)  a gap in a protoplanetary disk 
C)  a region of the interstellar medium cleared of material by supernovas 
D)  a region 10-100 Mpc across where the galaxy density is very low D

Question 3

Which of the following would increase the density of quasars at the present day?

Accepted Answer

A)  if more galaxies were ellipticals 
B)  if more galaxies were barred spirals 
C)  if more galaxies were isolated 
D)  if more galaxies were inside clusters 
A)  if more galaxies were ellipticals 
B)  if more galaxies were barred spirals 
C)  if more galaxies were isolated 
D)  if more galaxies were inside clusters B

Question 4

The figure below shows how the space density of a particular astronomical object depends on cosmic time.What kind of object does it show?

Accepted Answer

A)  spiral galaxies 
B)  heavy elements 
C)  quasars 
D)  stars 
A)  spiral galaxies 
B)  heavy elements 
C)  quasars 
D)  stars

Question 5

Suppose Hubble's constant was equal to 300 km/s/Mpc.If you approximate 1 Mpc = 3 x 10¹⁹ km,and 1 year = 3 x 10⁷ s,how old would the Universe be?

Accepted Answer

A)  500 Myr 
B)  3 Gyr 
C)  13 Gyr 
D)  50 Gyr 
A)  500 Myr 
B)  3 Gyr 
C)  13 Gyr 
D)  50 Gyr

Question 6

Which of the following discoveries disproved Aristotle's conception of an unchanging cosmos?

Accepted Answer

A)  the existence of galaxies 
B)  the finite speed of light 
C)  Hubble's law 
D)  the cosmic microwave background 
A)  the existence of galaxies 
B)  the finite speed of light 
C)  Hubble's law 
D)  the cosmic microwave background

Question 7

How has the rate at which galaxies interact with each other changed with time?

Accepted Answer

Collisions and other

Question 8

Which of the following statements is typically true of galaxy clusters?

Accepted Answer

A)  Most of their galaxies are large and bright. 
B)  The fraction of spiral galaxies increases toward the outskirts of clusters. 
C)  The pressure of their hot intracluster medium supports the galaxies against falling toward the center. 
D)  Most of their galaxies have ongoing star formation. 
A)  Most of their galaxies are large and bright. 
B)  The fraction of spiral galaxies increases toward the outskirts of clusters. 
C)  The pressure of their hot intracluster medium supports the galaxies against falling toward the center. 
D)  Most of their galaxies have ongoing star formation.

Question 9

Collisions are important in forming:

Accepted Answer

A)  elliptical galaxies. 
B)  galaxy groups. 
C)  galaxy clusters. 
D)  barred spiral galaxies. 
A)  elliptical galaxies. 
B)  galaxy groups. 
C)  galaxy clusters. 
D)  barred spiral galaxies.

Question 10

Which physical law allows astronomers to probe the Universe's past?

Accepted Answer

A)  gravitational lensing 
B)  the Doppler effect 
C)  the finite speed of light 
D)  the inverse square law 
A)  gravitational lensing 
B)  the Doppler effect 
C)  the finite speed of light 
D)  the inverse square law

Question 11

A region 1 Mpc across contains a total mass of 10¹³ MSᵤn.What kind of object is this most likely to be?

Accepted Answer

A)  a spiral galaxy 
B)  an elliptical galaxy 
C)  a galaxy group 
D)  a galaxy cluster 
A)  a spiral galaxy 
B)  an elliptical galaxy 
C)  a galaxy group 
D)  a galaxy cluster

Question 12

Each point in the image below represents a galaxy on the sky,with the Earth at the bottom point of the "pie piece" and distance away from that point representing distance from Earth.What is the prominent set of galaxies in a straight line away from the observer most likely to be?

Accepted Answer

A)  a filament 
B)  a galaxy cluster 
C)  a void 
D)  an active galactic nucleus 
A)  a filament 
B)  a galaxy cluster 
C)  a void 
D)  an active galactic nucleus

Question 13

If the galaxy cluster in the figure below is perfectly spherical,how will the object appear to the observer?

Accepted Answer

As an Eins

Question 14

An astronomer detects a starburst galaxy with an irregular shape.She might reasonably conclude that it:

Accepted Answer

A)  is the collision of two spiral galaxies. 
B)  has primarily red stars. 
C)  has very little interstellar gas. 
D)  will eventually form a spiral galaxy. 
A)  is the collision of two spiral galaxies. 
B)  has primarily red stars. 
C)  has very little interstellar gas. 
D)  will eventually form a spiral galaxy.

Question 15

What is the relative abundance of mass in stars,gas,and dark matter within galaxy clusters?

Accepted Answer

A)  10 percent stars, 1 percent gas, 89 percent dark matter 
B)  10 percent stars, 10 percent gas, 80 percent dark matter 
C)  1 percent stars, 1 percent gas, 98 percent dark matter 
D)  1 percent stars, 10 percent gas, 89 percent dark matter 
A)  10 percent stars, 1 percent gas, 89 percent dark matter 
B)  10 percent stars, 10 percent gas, 80 percent dark matter 
C)  1 percent stars, 1 percent gas, 98 percent dark matter 
D)  1 percent stars, 10 percent gas, 89 percent dark matter

Question 16

Each point in the image below represents a galaxy on the sky,with the Earth at the bottom point of the "pie piece" and distance away from that point representing distance from Earth.This map was made using:

Accepted Answer

A)  parallax. 
B)  spectroscopic parallax. 
C)  Hubble's law. 
D)  Cepheid variables. 
A)  parallax. 
B)  spectroscopic parallax. 
C)  Hubble's law. 
D)  Cepheid variables.

Question 17

Imagine that an astronomer in an alternate universe observes all galaxies to be blueshifted relative to the Milky Way.Which of the following would this imply?

Accepted Answer

A)  The Big Bang happened in the recent past. 
B)  Space is contracting. 
C)  The Milky Way is the center of the universe. 
D)  Galaxies do not rotate 
A)  The Big Bang happened in the recent past. 
B)  Space is contracting. 
C)  The Milky Way is the center of the universe. 
D)  Galaxies do not rotate

Question 18

The Hubble Deep Field has revealed that:

Accepted Answer

A)  galaxy clusters assembled early in the Universe's history. 
B)  starbursts were more common in the early Universe. 
C)  quasars were more common in the early Universe. 
D)  all of the above 
A)  galaxy clusters assembled early in the Universe's history. 
B)  starbursts were more common in the early Universe. 
C)  quasars were more common in the early Universe. 
D)  all of the above

Question 19

An astronomer observes 1,000 galaxies positioned within 5 Mpc of each other in a galaxy cluster.What other quantity or quantities should he or she measure to determine the mass of this cluster?

Accepted Answer

The typica

Question 20

In what sense is the Universe homogeneous?

Accepted Answer

When averaged over very large

How do astronomers know that dark matter is "cold"?

Which of the following describes a void?

Which of the following would increase the density of quasars at the present day?

The figure below shows how the space density of a particular astronomical object depends on cosmic time.What kind of object does it show?

Suppose Hubble's constant was equal to 300 km/s/Mpc.If you approximate 1 Mpc = 3 x 10¹⁹ km,and 1 year = 3 x 10⁷ s,how old would the Universe be?

Which of the following discoveries disproved Aristotle's conception of an unchanging cosmos?

How has the rate at which galaxies interact with each other changed with time?

Which of the following statements is typically true of galaxy clusters?

Collisions are important in forming:

Which physical law allows astronomers to probe the Universe's past?

A region 1 Mpc across contains a total mass of 10¹³ MSᵤn.What kind of object is this most likely to be?

Each point in the image below represents a galaxy on the sky,with the Earth at the bottom point of the "pie piece" and distance away from that point representing distance from Earth.What is the prominent set of galaxies in a straight line away from the observer most likely to be?

If the galaxy cluster in the figure below is perfectly spherical,how will the object appear to the observer?

An astronomer detects a starburst galaxy with an irregular shape.She might reasonably conclude that it:

What is the relative abundance of mass in stars,gas,and dark matter within galaxy clusters?

Each point in the image below represents a galaxy on the sky,with the Earth at the bottom point of the "pie piece" and distance away from that point representing distance from Earth.This map was made using:

Imagine that an astronomer in an alternate universe observes all galaxies to be blueshifted relative to the Milky Way.Which of the following would this imply?

The Hubble Deep Field has revealed that:

An astronomer observes 1,000 galaxies positioned within 5 Mpc of each other in a galaxy cluster.What other quantity or quantities should he or she measure to determine the mass of this cluster?

In what sense is the Universe homogeneous?

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

A Universe of Galaxies

Cosmology

Filters

Exam 17: The Cosmic Web: the Large-Scale Structure of the Universe

How do astronomers know that dark matter is "cold"?

Which of the following describes a void?

Which of the following would increase the density of quasars at the present day?

The figure below shows how the space density of a particular astronomical object depends on cosmic time.What kind of object does it show?

Suppose Hubble's constant was equal to 300 km/s/Mpc.If you approximate 1 Mpc = 3 x 10¹⁹ km,and 1 year = 3 x 10⁷ s,how old would the Universe be?

Which of the following discoveries disproved Aristotle's conception of an unchanging cosmos?

How has the rate at which galaxies interact with each other changed with time?

Which of the following statements is typically true of galaxy clusters?

Collisions are important in forming:

Which physical law allows astronomers to probe the Universe's past?

A region 1 Mpc across contains a total mass of 10¹³ MSᵤn.What kind of object is this most likely to be?

Each point in the image below represents a galaxy on the sky,with the Earth at the bottom point of the "pie piece" and distance away from that point representing distance from Earth.What is the prominent set of galaxies in a straight line away from the observer most likely to be?

If the galaxy cluster in the figure below is perfectly spherical,how will the object appear to the observer?

An astronomer detects a starburst galaxy with an irregular shape.She might reasonably conclude that it:

What is the relative abundance of mass in stars,gas,and dark matter within galaxy clusters?

Each point in the image below represents a galaxy on the sky,with the Earth at the bottom point of the "pie piece" and distance away from that point representing distance from Earth.This map was made using:

Imagine that an astronomer in an alternate universe observes all galaxies to be blueshifted relative to the Milky Way.Which of the following would this imply?

The Hubble Deep Field has revealed that:

An astronomer observes 1,000 galaxies positioned within 5 Mpc of each other in a galaxy cluster.What other quantity or quantities should he or she measure to determine the mass of this cluster?

In what sense is the Universe homogeneous?

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

A Universe of Galaxies

Cosmology

Filters