Question 1

What is the primary factor in determining the classification for an elliptical galaxy?

Accepted Answer

A)  size 
B)  shape 
C)  mass 
D)  color 
A)  size 
B)  shape 
C)  mass 
D)  color

Question 2

Active galaxy radio lobes and jets contain magnetic fields.

Accepted Answer

A) True 
 B)False

Question 3

The hydrogen Balmer line H β  has a wavelength of 486.1 nm in the laboratory. It is observed in a quasar at 2430.5 nm. What is the fractional change in wavelength or redshift z of this quasar?

Accepted Answer

A)  5 
B)  0.5 
C)  0.25 
D)  4 
E)  1944.4 
A)  5 
B)  0.5 
C)  0.25 
D)  4 
E)  1944.4

Question 4

The high _______________ of quasars reveals to astronomers that they must be very distant.

Accepted Answer

The answer of The high _______________ of quasars reveals to...

Question 5

Why do astronomers believe supermassive black holes are the source of an AGN's energy?

Accepted Answer

A)  Such black holes have been found at the center of most galaxies, both active and inactive. 
B)  Radio jets are seen from low-mass black holes plus accretion disks inside our galaxy. 
C)  Jets and accretion disks have been observed in active galaxies. 
D)  Black holes can produce so much energy in such a small place. 
E)  All of the other choices are correct. 
A)  Such black holes have been found at the center of most galaxies, both active and inactive. 
B)  Radio jets are seen from low-mass black holes plus accretion disks inside our galaxy. 
C)  Jets and accretion disks have been observed in active galaxies. 
D)  Black holes can produce so much energy in such a small place. 
E)  All of the other choices are correct.

Question 6

Gravitational lensing

Accepted Answer

A)  occurs when light passes near a massive object and is deflected by the object's gravitational field. 
B)  can be used to determine the luminosity of a galaxy. 
C)  occurs when the mass of a galaxy is greater than expected from the luminosity of the galaxy. 
D)  occurs when the mass of a galaxy is less than expected from the luminosity of the galaxy. 
E)  can be used to determine the recessional velocity of a galaxy. 
A)  occurs when light passes near a massive object and is deflected by the object's gravitational field. 
B)  can be used to determine the luminosity of a galaxy. 
C)  occurs when the mass of a galaxy is greater than expected from the luminosity of the galaxy. 
D)  occurs when the mass of a galaxy is less than expected from the luminosity of the galaxy. 
E)  can be used to determine the recessional velocity of a galaxy.

Question 7

Astronomers now speculate that a galaxy's shape depends on all of the following except

Accepted Answer

A)  the rate of star formation. 
B)  the history of past collisions. 
C)  the mass. 
D)  All of the other choices may be important in determining a galaxy's shape. 
A)  the rate of star formation. 
B)  the history of past collisions. 
C)  the mass. 
D)  All of the other choices may be important in determining a galaxy's shape.

Question 8

What distance method did Edwin Hubble use to determine the distance to local galaxies?

Accepted Answer

A)  Hubble law 
B)  supernova observations 
C)  period-luminosity relationship of variable stars 
D)  parallax 
A)  Hubble law 
B)  supernova observations 
C)  period-luminosity relationship of variable stars 
D)  parallax

Question 9

In the double-exhaust model, the radio lobes of a radio galaxy are inflated by

Accepted Answer

A)  jets of excited gas flowing from the central galaxy. 
B)  jets of high-energy sound waves flowing from the central galaxy. 
C)  a disk of ionized material that orbits very near a supermassive black hole. 
D)  dark clouds of very cold gas and dust. 
E)  None of the other choices are correct. 
A)  jets of excited gas flowing from the central galaxy. 
B)  jets of high-energy sound waves flowing from the central galaxy. 
C)  a disk of ionized material that orbits very near a supermassive black hole. 
D)  dark clouds of very cold gas and dust. 
E)  None of the other choices are correct.

Question 10

When two galaxies collide, they pass through each other and their stars almost never collide.

Accepted Answer

A) True 
 B)False

Question 11

___________ are produced when two galaxies pass near each other and pull large streamers of stars, gas, and dust away from the galaxies.

Accepted Answer

A)  Ring galaxies 
B)  Spiral galaxies 
C)  Rotation curves 
D)  Tidal tails 
E)  Irregular galaxies 
A)  Ring galaxies 
B)  Spiral galaxies 
C)  Rotation curves 
D)  Tidal tails 
E)  Irregular galaxies

Question 12

An elliptical galaxy could

Accepted Answer

A)  evolve into an irregular galaxy when it has used up all of its gas and dust. 
B)  be formed from the collision and merger of spiral galaxies. 
C)  evolve from a single spiral galaxy when the spiral has used up all of its gas and dust. 
D)  become a starburst galaxy if it were to move through the hot intergalactic medium of a cluster. 
E)  evolve from an S0 galaxy if the S0 galaxy were to increase its rotation rate. 
A)  evolve into an irregular galaxy when it has used up all of its gas and dust. 
B)  be formed from the collision and merger of spiral galaxies. 
C)  evolve from a single spiral galaxy when the spiral has used up all of its gas and dust. 
D)  become a starburst galaxy if it were to move through the hot intergalactic medium of a cluster. 
E)  evolve from an S0 galaxy if the S0 galaxy were to increase its rotation rate.

Question 13

Of the following, which of the following is the largest object?

Accepted Answer

A)  the Milky Way galaxy 
B)  the Large Magellanic Cloud 
C)  the Local Group 
D)  the Andromeda galaxy 
A)  the Milky Way galaxy 
B)  the Large Magellanic Cloud 
C)  the Local Group 
D)  the Andromeda galaxy

Question 14

The Large and Small Magellanic Clouds are satellites galaxies of the Milky Way.

Accepted Answer

A) True 
 B)False

Question 15

The Local Group of galaxies is dominated by the presence of spiral galaxies.

Accepted Answer

A) True 
 B)False

Question 16

Centaurus A is a radio galaxy that has a visible galaxy at the center. This central elliptical galaxy of Centaurus A is encircled by a ring of gas and dust, different from most elliptical galaxies. The dust ring orbits about an axis that is perpendicular to the axis of rotation of the elliptical galaxy. What does this suggest about this central elliptical galaxy of Centaurus A?

Accepted Answer

A)  The radio jets have caused the dust disk to be driven around the elliptical galaxy. 
B)  There are at least two black holes at the center of the elliptical galaxy. 
C)  Centaurus A is probably the result of a merger of an elliptical galaxy and a spiral galaxy. 
D)  Dust is produced as the jets interact with the intergalactic medium. 
E)  Elliptical galaxies often contain dust that forms a disk along their rotation axis. 
A)  The radio jets have caused the dust disk to be driven around the elliptical galaxy. 
B)  There are at least two black holes at the center of the elliptical galaxy. 
C)  Centaurus A is probably the result of a merger of an elliptical galaxy and a spiral galaxy. 
D)  Dust is produced as the jets interact with the intergalactic medium. 
E)  Elliptical galaxies often contain dust that forms a disk along their rotation axis.

Question 17

Many disk galaxies, such as Andromeda and the Milky Way, are thought to have extended halos of dark matter because the disk circular orbital speed is observed to ____________ increasing distances from the disk center.

Accepted Answer

A)  stay constant with 
B)  decrease with 
C)  be totally absent at 
A)  stay constant with 
B)  decrease with 
C)  be totally absent at

Question 18

In the above image, the _____________ is the gravitational lens and the ___________ is the lensed object.

Accepted Answer

A)  distant galaxy, cluster 
B)  cluster, distant galaxy 
C)  cluster, star 
D)  star, cluster 
A)  distant galaxy, cluster 
B)  cluster, distant galaxy 
C)  cluster, star 
D)  star, cluster

Question 19

The fact that many radio lobes emit more intensely from the side away from the galaxy suggests that

Accepted Answer

A)  they are formed by material falling into the galaxy. 
B)  they are powered by magnetic fields. 
C)  they are excited by radiation from nearby galaxies. 
D)  they are powered by the rapid rotation of the galaxy. 
E)  they are created by jets from the galaxy emitting where the material is halted. 
A)  they are formed by material falling into the galaxy. 
B)  they are powered by magnetic fields. 
C)  they are excited by radiation from nearby galaxies. 
D)  they are powered by the rapid rotation of the galaxy. 
E)  they are created by jets from the galaxy emitting where the material is halted.

Question 20

Galaxies may contain a supermassive black hole at their center but ___________ an active nucleus because of ____________ into the black hole

Accepted Answer

A)  show; mass inflow 
B)  not show; mass inflow 
C)  show; lack of mass inflow 
A)  show; mass inflow 
B)  not show; mass inflow 
C)  show; lack of mass inflow

What is the primary factor in determining the classification for an elliptical galaxy?

Active galaxy radio lobes and jets contain magnetic fields.

The hydrogen Balmer line H_β has a wavelength of 486.1 nm in the laboratory. It is observed in a quasar at 2430.5 nm. What is the fractional change in wavelength or redshift z of this quasar?

The high _______________ of quasars reveals to astronomers that they must be very distant.

Why do astronomers believe supermassive black holes are the source of an AGN's energy?

Gravitational lensing

Astronomers now speculate that a galaxy's shape depends on all of the following except

What distance method did Edwin Hubble use to determine the distance to local galaxies?

In the double-exhaust model, the radio lobes of a radio galaxy are inflated by

When two galaxies collide, they pass through each other and their stars almost never collide.

___________ are produced when two galaxies pass near each other and pull large streamers of stars, gas, and dust away from the galaxies.

An elliptical galaxy could

Of the following, which of the following is the largest object?

The Large and Small Magellanic Clouds are satellites galaxies of the Milky Way.

The Local Group of galaxies is dominated by the presence of spiral galaxies.

Many disk galaxies, such as Andromeda and the Milky Way, are thought to have extended halos of dark matter because the disk circular orbital speed is observed to ____________ increasing distances from the disk center.

In the above image, the ___ is the gravitational lens and the _ is the lensed object.

The fact that many radio lobes emit more intensely from the side away from the galaxy suggests that

Galaxies may contain a supermassive black hole at their center but _ an active nucleus because of __ into the black hole

Here and Now

A Users Guide to the Sky

Cycles of the Sun and Moon

The Origin of Modern Astronomy

Light and Telescopes

Atoms and Spectra

The Sun

The Family of Stars

The Formation and Structure of Stars

The Deaths of Stars

Neutron Stars and Black Holes

The Milky Way Galaxy

Modern Cosmology

Origin of the Solar System and Extrasolar Planets

Earth and Moon: Bases for Comparative Planetology

Mercury, Venus, and Mars

The Outer Solar System

Meteorites, Asteroids, and Comets

Astrobiology: Life on Other Worlds

Filters

Exam 13: Galaxies: Normal and Active

What is the primary factor in determining the classification for an elliptical galaxy?

Active galaxy radio lobes and jets contain magnetic fields.

The hydrogen Balmer line H β has a wavelength of 486.1 nm in the laboratory. It is observed in a quasar at 2430.5 nm. What is the fractional change in wavelength or redshift z of this quasar?

The high _______________ of quasars reveals to astronomers that they must be very distant.

Why do astronomers believe supermassive black holes are the source of an AGN's energy?

Gravitational lensing

Astronomers now speculate that a galaxy's shape depends on all of the following except

What distance method did Edwin Hubble use to determine the distance to local galaxies?

In the double-exhaust model, the radio lobes of a radio galaxy are inflated by

When two galaxies collide, they pass through each other and their stars almost never collide.

___________ are produced when two galaxies pass near each other and pull large streamers of stars, gas, and dust away from the galaxies.

An elliptical galaxy could

Of the following, which of the following is the largest object?

The Large and Small Magellanic Clouds are satellites galaxies of the Milky Way.

The Local Group of galaxies is dominated by the presence of spiral galaxies.

Many disk galaxies, such as Andromeda and the Milky Way, are thought to have extended halos of dark matter because the disk circular orbital speed is observed to ____________ increasing distances from the disk center.

In the above image, the _____________ is the gravitational lens and the ___________ is the lensed object.

The fact that many radio lobes emit more intensely from the side away from the galaxy suggests that

Galaxies may contain a supermassive black hole at their center but ___________ an active nucleus because of ____________ into the black hole

Here and Now

A Users Guide to the Sky

Cycles of the Sun and Moon

The Origin of Modern Astronomy

Light and Telescopes

Atoms and Spectra

The Sun

The Family of Stars

The Formation and Structure of Stars

The Deaths of Stars

Neutron Stars and Black Holes

The Milky Way Galaxy

Modern Cosmology

Origin of the Solar System and Extrasolar Planets

Earth and Moon: Bases for Comparative Planetology

Mercury, Venus, and Mars

The Outer Solar System

Meteorites, Asteroids, and Comets

Astrobiology: Life on Other Worlds

Filters

The hydrogen Balmer line H_β has a wavelength of 486.1 nm in the laboratory. It is observed in a quasar at 2430.5 nm. What is the fractional change in wavelength or redshift z of this quasar?

In the above image, the ___ is the gravitational lens and the _ is the lensed object.

Galaxies may contain a supermassive black hole at their center but _ an active nucleus because of __ into the black hole