Question 1

Explain why a galaxy can collapse to a much smaller size than its dark matter halo.

Accepted Answer

Dark matter collapses down until it is s

Question 2

Which of these statements about black holes in the early universe is NOT true?

Accepted Answer

A) Supermassive black holes affected the star formation rates in early galaxies. 
B) The growth of supermassive black holes is likely linked with galaxy mergers. 
C) The first generation of stars had high enough masses to leave black holes behind after exploding as supernova. 
D) The black holes in the early universe should have been larger than those seen today. 
E) Supermassive black holes may have formed from mergers of smaller black holes. 
A) Supermassive black holes affected the star formation rates in early galaxies. 
B) The growth of supermassive black holes is likely linked with galaxy mergers. 
C) The first generation of stars had high enough masses to leave black holes behind after exploding as supernova. 
D) The black holes in the early universe should have been larger than those seen today. 
E) Supermassive black holes may have formed from mergers of smaller black holes.

Question 3

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 4

How do astronomers explain the formation of elliptical galaxies?

Accepted Answer

Elliptical galaxies most likely formed a

Question 5

Astronomers have determined that the Milky Way is being pulled toward a massive structure called the "Great Attractor" due to the mass of the Great Attractor alone.

Accepted Answer

A) True 
 B)False

Question 6

Which probably formed last in the course of the evolution of the universe?

Accepted Answer

A) a typical proton inside a water molecule on the Earth 
B) a helium atom on the surface of the Sun 
C) a typical star that is a member of a globular cluster star in our Milky Way 
D) the Milky Way 
E) the Virgo Supercluster 
A) a typical proton inside a water molecule on the Earth 
B) a helium atom on the surface of the Sun 
C) a typical star that is a member of a globular cluster star in our Milky Way 
D) the Milky Way 
E) the Virgo Supercluster

Question 7

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

Question 8

In the future,we expect our universe will go through the ___________ era,when most of the normal matter in the universe is locked up in brown dwarfs,white dwarfs,neutron stars,and black holes.

Accepted Answer

A) remnant 
B) neutral 
C) degenerate 
D) retirement 
E) quiet 
A) remnant 
B) neutral 
C) degenerate 
D) retirement 
E) quiet

Question 9

If astronomers discover a new ultrafaint galaxy,where would it most likely be found?

Accepted Answer

A) on its own,away from other galaxies 
B) a few billion light years away from Earth 
C) at high redshift 
D) in a large galaxy cluster 
E) orbiting the Milky Way 
A) on its own,away from other galaxies 
B) a few billion light years away from Earth 
C) at high redshift 
D) in a large galaxy cluster 
E) orbiting the Milky Way

Question 10

How much of the total mass of the universe is made up of hot dark matter?

Accepted Answer

A) less than 1 percent 
B) 5 percent 
C) 25 percent 
D) 45 percent 
E) 90 percent 
A) less than 1 percent 
B) 5 percent 
C) 25 percent 
D) 45 percent 
E) 90 percent

Question 11

Describe two ways in which you could measure the mass of a galaxy cluster.

Accepted Answer

Here are three possible answers:
(1)Dete

Question 12

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 13

Which of these shows the correct order of collections of galaxies,starting with the smallest and ending with the 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

Question 14

There are fluctuations in the CMB due to the fact that clumps of dark matter had already begun to form in the universe when the light from the CMB was given off.

Accepted Answer

A) True 
 B)False

Question 15

Current theoretical models suggest that most of the universe is composed of hot dark matter.

Accepted Answer

A) True 
 B)False

Question 16

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 collisions. 
B) Dark matter is mostly made 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 collisions. 
B) Dark matter is mostly made 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 17

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 18

The Local Group is a part of the Virgo Supercluster.

Accepted Answer

A) True 
 B)False

Question 19

Structure formation in the universe proceeds hierarchically,meaning that:

Accepted Answer

A) large objects collapse then fragment to form smaller objects 
B) large objects form at the same times as smaller objects 
C) small objects collapse then merge to form larger objects 
D) only small objects form and are stable over time 
E) normal matter collapses first and dark matter collapses later 
A) large objects collapse then fragment to form smaller objects 
B) large objects form at the same times as smaller objects 
C) small objects collapse then merge to form larger objects 
D) only small objects form and are stable over time 
E) normal matter collapses first and dark matter collapses later

Exam 23: Large-Scale Structure in the Universe

Explain why a galaxy can collapse to a much smaller size than its dark matter halo.

Which of these statements about black holes in the early universe is NOT true?

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

How do astronomers explain the formation of elliptical galaxies?

Astronomers have determined that the Milky Way is being pulled toward a massive structure called the "Great Attractor" due to the mass of the Great Attractor alone.

Which probably formed last in the course of the evolution of the universe?

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

In the future,we expect our universe will go through the ___________ era,when most of the normal matter in the universe is locked up in brown dwarfs,white dwarfs,neutron stars,and black holes.

If astronomers discover a new ultrafaint galaxy,where would it most likely be found?

How much of the total mass of the universe is made up of hot dark matter?

Describe two ways in which you could measure the mass of a galaxy cluster.

Structure formation in our universe:

Which of these shows the correct order of collections of galaxies,starting with the smallest and ending with the largest?

There are fluctuations in the CMB due to the fact that clumps of dark matter had already begun to form in the universe when the light from the CMB was given off.

Current theoretical models suggest that most of the universe is composed of hot dark matter.

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

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

The Local Group is a part of the Virgo Supercluster.

Structure formation in the universe proceeds hierarchically,meaning that:

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