Question 1

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 2

Which distance indicator technique is best to find distances to galaxies

Accepted Answer

A) Cepheid variables 
B) radar 
C) small-angle formula 
D) magnitude-distance formula 
A) Cepheid variables 
B) radar 
C) small-angle formula 
D) magnitude-distance formula

Question 3

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 4

-The red line shown above is shifted 15.8% from the blue dashed line. If Hβ is 486.1 nm, what is the change in the wavelength

Accepted Answer

A) 562.9 nm 
B) 76.8 nm 
C) 486.1 nm 
D) 409.3 nm 
A) 562.9 nm 
B) 76.8 nm 
C) 486.1 nm 
D) 409.3 nm

Question 5

What evidence do we have that large galaxies cannibalize small galaxies

Accepted Answer

Giant elliptical galaxies in r

Question 6

___________ is (are) observed when light from a distant quasar travels past a massive galaxy between us and the quasar, and this light is focused to form two or more images of the same quasar.

Accepted Answer

A) A double-lobed radio galaxy 
B) Superluminal expansion 
C) The gravitational lens effect 
D) A blazar 
E) Gravitational waves 
A) A double-lobed radio galaxy 
B) Superluminal expansion 
C) The gravitational lens effect 
D) A blazar 
E) Gravitational waves

Question 7

The hydrogen Balmer line Hβ 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 8

When discovered in the 1960's, a(n) ___________ was found to emit large amounts of energy, but through visual and radio telescopes appeared to be a single point of light much like a star.

Accepted Answer

A) a planet like Venus 
B) E galaxy 
C) spiral galaxy 
D) double-lobed radio galaxy 
E) quasar 
A) a planet like Venus 
B) E galaxy 
C) spiral galaxy 
D) double-lobed radio galaxy 
E) quasar

Question 9

The above visual wavelength image of a counter-clockwise rotating spiral galaxy indicates that the blueshifted emission lines are the dashed lines above the solid black horizontal line in the right panel and the redshifted emission lines are the dashed lines below the solid black horizontal line.

Accepted Answer

A) True 
 B)False

Question 10

-The shells indicated in the enhanced visual wavelength image shown above are formed from _____________.

Accepted Answer

A) quasars 
B) mergers of galaxies 
C) tides 
D) spiral arms 
A) quasars 
B) mergers of galaxies 
C) tides 
D) spiral arms

Question 11

Poor clusters

Accepted Answer

A) contain more than 1000 stars and are found in the halo of the galaxy. 
B) contain lots of young stars and are found in the disk of a spiral galaxy. 
C) contain more than 1000 galaxies and are generally elliptical in shape. 
D) contain fewer than 1000 galaxies and tend to be irregularly shaped. 
E) are found in the nucleus of the galaxy. 
A) contain more than 1000 stars and are found in the halo of the galaxy. 
B) contain lots of young stars and are found in the disk of a spiral galaxy. 
C) contain more than 1000 galaxies and are generally elliptical in shape. 
D) contain fewer than 1000 galaxies and tend to be irregularly shaped. 
E) are found in the nucleus of the galaxy.

Question 12

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 13

If the absolute magnitude, M, of a supernova is −19 and a galaxy is found that contains a supernova with an apparent magnitude, m, of 16. What is the distance to the galaxy Hint: dpc = $10^{(m - M + 5)/5}$

Accepted Answer

A) 100 AU 
B) 100 pc 
C) 100 ly 
D) 100 kpc 
E) 100 Mpc 
A) 100 AU 
B) 100 pc 
C) 100 ly 
D) 100 kpc 
E) 100 Mpc

Question 14

Discuss the observational differences between spiral, elliptical, and irregular galaxies.

Accepted Answer

Elliptical galaxies (class E) have no di

Question 15

Statistical evidence

Accepted Answer

A) can be used to draw conclusions about a specific cases. 
B) is applicable to classes of objects where only a few objects from the class have been studied. 
C) allows scientists to determine the mechanism that produces the dust ring in Centaurus A. 
D) allows scientists to deduce general characteristics about a class of objects with similar properties. 
E) provides insight into the behavior of an individual object based on careful observations of it. 
A) can be used to draw conclusions about a specific cases. 
B) is applicable to classes of objects where only a few objects from the class have been studied. 
C) allows scientists to determine the mechanism that produces the dust ring in Centaurus A. 
D) allows scientists to deduce general characteristics about a class of objects with similar properties. 
E) provides insight into the behavior of an individual object based on careful observations of it.

Question 16

The figure shows an image of a galaxy at dust-penetrating wavelengths. It can be classified as which one of the following galactic types

Accepted Answer

A) spiral 
B) irregular 
C) elliptical 
D) red giant 
A) spiral 
B) irregular 
C) elliptical 
D) red giant

Question 17

Why are there few quasars at low redshifts and at high redshifts but many at redshifts of about 2

Accepted Answer

Quasars are most common with redshifts o

Question 18

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 19

Which kind of active galaxies has been observed at the greatest distances from us

Accepted Answer

A) Seyfert galaxies 
B) radio galaxies 
C) quasars 
A) Seyfert galaxies 
B) radio galaxies 
C) quasars

Question 20

Recent high resolution radio observations show that quasars can be classified as

Accepted Answer

A) exploding supernova stars. 
B) exploding planets. 
C) normal galaxies like our Milky Way Galaxy. 
D) a kind of active galaxy similar to Seyfert and radio galaxies. 
A) exploding supernova stars. 
B) exploding planets. 
C) normal galaxies like our Milky Way Galaxy. 
D) a kind of active galaxy similar to Seyfert and radio galaxies.

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

Which distance indicator technique is best to find distances to galaxies

-The red line shown above is shifted 15.8% from the blue dashed line. If Hβ is 486.1 nm, what is the change in the wavelength

What evidence do we have that large galaxies cannibalize small galaxies

___________ is (are) observed when light from a distant quasar travels past a massive galaxy between us and the quasar, and this light is focused to form two or more images of the same quasar.

The hydrogen Balmer line Hβ 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

When discovered in the 1960's, a(n) ___________ was found to emit large amounts of energy, but through visual and radio telescopes appeared to be a single point of light much like a star.

The above visual wavelength image of a counter-clockwise rotating spiral galaxy indicates that the blueshifted emission lines are the dashed lines above the solid black horizontal line in the right panel and the redshifted emission lines are the dashed lines below the solid black horizontal line.

-The shells indicated in the enhanced visual wavelength image shown above are formed from _____________.

Poor clusters

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

If the absolute magnitude, M, of a supernova is −19 and a galaxy is found that contains a supernova with an apparent magnitude, m, of 16. What is the distance to the galaxy Hint: dpc = $10^{(m - M + 5)/5}$

Discuss the observational differences between spiral, elliptical, and irregular galaxies.

Statistical evidence

The figure shows an image of a galaxy at dust-penetrating wavelengths. It can be classified as which one of the following galactic types

Why are there few quasars at low redshifts and at high redshifts but many at redshifts of about 2

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

Which kind of active galaxies has been observed at the greatest distances from us

Recent high resolution radio observations show that quasars can be classified as

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

The Origin of the Solar System

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

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

Which distance indicator technique is best to find distances to galaxies

-The red line shown above is shifted 15.8% from the blue dashed line. If Hβ is 486.1 nm, what is the change in the wavelength

What evidence do we have that large galaxies cannibalize small galaxies

___________ is (are) observed when light from a distant quasar travels past a massive galaxy between us and the quasar, and this light is focused to form two or more images of the same quasar.

The hydrogen Balmer line Hβ 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

When discovered in the 1960's, a(n) ___________ was found to emit large amounts of energy, but through visual and radio telescopes appeared to be a single point of light much like a star.

The above visual wavelength image of a counter-clockwise rotating spiral galaxy indicates that the blueshifted emission lines are the dashed lines above the solid black horizontal line in the right panel and the redshifted emission lines are the dashed lines below the solid black horizontal line.

-The shells indicated in the enhanced visual wavelength image shown above are formed from _____________.

Poor clusters

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

If the absolute magnitude, M, of a supernova is −19 and a galaxy is found that contains a supernova with an apparent magnitude, m, of 16. What is the distance to the galaxy Hint: dpc = 10(m−M+5)/510^{(m - M + 5)/5}10(m−M+5)/5

Discuss the observational differences between spiral, elliptical, and irregular galaxies.

Statistical evidence

The figure shows an image of a galaxy at dust-penetrating wavelengths. It can be classified as which one of the following galactic types

Why are there few quasars at low redshifts and at high redshifts but many at redshifts of about 2

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

Which kind of active galaxies has been observed at the greatest distances from us

Recent high resolution radio observations show that quasars can be classified as

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

The Origin of the Solar System

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

If the absolute magnitude, M, of a supernova is −19 and a galaxy is found that contains a supernova with an apparent magnitude, m, of 16. What is the distance to the galaxy Hint: dpc = $10^{(m - M + 5)/5}$