Question 1

Quasars are:

Accepted Answer

A)  sources of great energy, very large in actual size, and shaped like galaxies. 
B)  sources of intense radio energy only, not visible at other wavelengths, and relatively large but very distant. 
C)  prolific sources of energy, starlike in appearance, and intrinsically small. 
D)  starlike sources of great energy located in the Milky Way Galaxy and intrinsically very small. 
A)  sources of great energy, very large in actual size, and shaped like galaxies. 
B)  sources of intense radio energy only, not visible at other wavelengths, and relatively large but very distant. 
C)  prolific sources of energy, starlike in appearance, and intrinsically small. 
D)  starlike sources of great energy located in the Milky Way Galaxy and intrinsically very small.

Question 2

What is the present belief about the location of the Milky Way Galaxy?

Accepted Answer

A)  The Milky Way has been shown to be in the center of the universe by the uniformity of the Hubble flow as seen from Earth. 
B)  The Milky Way has been shown not to be in the center of the universe by the uniformity of the Hubble flow as seen from Earth. 
C)  The Milky Way has been shown to be in the center of the universe by the distribution of superclusters as seen from Earth. 
D)  The Milky Way has been shown not to be in the center of the universe by the distribution of superclusters as seen from Earth. 
A)  The Milky Way has been shown to be in the center of the universe by the uniformity of the Hubble flow as seen from Earth. 
B)  The Milky Way has been shown not to be in the center of the universe by the uniformity of the Hubble flow as seen from Earth. 
C)  The Milky Way has been shown to be in the center of the universe by the distribution of superclusters as seen from Earth. 
D)  The Milky Way has been shown not to be in the center of the universe by the distribution of superclusters as seen from Earth.

Question 3

The spectrum of a BL Lacertae object shows:

Accepted Answer

A)  strong, highly redshifted emission lines. 
B)  doubled emission lines split by the Doppler shift from oppositely directed jets of material. 
C)  absorption lines of highly ionized atoms. 
D)  a smooth continuum with no recognizable features. 
A)  strong, highly redshifted emission lines. 
B)  doubled emission lines split by the Doppler shift from oppositely directed jets of material. 
C)  absorption lines of highly ionized atoms. 
D)  a smooth continuum with no recognizable features.

Question 4

"Standard candles," which are important for finding distances to remote galaxies,are:

Accepted Answer

A)  stars and other objects of known intrinsic brightness. 
B)  standard laboratory light sources with which the brightness of a galaxy can be compared. 
C)  standard bars of known length with which the size of a galaxy can be measured. 
D)  heat sources used for calibrating infrared observations of galaxies. 
A)  stars and other objects of known intrinsic brightness. 
B)  standard laboratory light sources with which the brightness of a galaxy can be compared. 
C)  standard bars of known length with which the size of a galaxy can be measured. 
D)  heat sources used for calibrating infrared observations of galaxies.

Question 5

Which statement about clusters of galaxies is TRUE?

Accepted Answer

A)  The observed mass of the galaxies of the cluster is many thousands of times too small to hold the cluster together. 
B)  The observed mass of the galaxies of the cluster is about 10 times larger than the amount needed to hold the cluster together. 
C)  The observed mass of the galaxies in the cluster is about 10 times too small to hold the cluster together. 
D)  The observed mass of the galaxies of the cluster is almost exactly equal to the mass needed to hold the cluster together. 
A)  The observed mass of the galaxies of the cluster is many thousands of times too small to hold the cluster together. 
B)  The observed mass of the galaxies of the cluster is about 10 times larger than the amount needed to hold the cluster together. 
C)  The observed mass of the galaxies in the cluster is about 10 times too small to hold the cluster together. 
D)  The observed mass of the galaxies of the cluster is almost exactly equal to the mass needed to hold the cluster together.

Question 6

Who first discovered that many galaxies are moving away from Earth?

Accepted Answer

A)  Karl Jansky 
B)  V. M. Slipher 
C)  Albert Einstein 
D)  Edwin Hubble 
A)  Karl Jansky 
B)  V. M. Slipher 
C)  Albert Einstein 
D)  Edwin Hubble

Question 7

The halo of the Milky Way Galaxy consists of a number of objects that orbit the galactic center and periodically pass through the galactic plane.Which objects are NOT among the galactic halo objects?

Accepted Answer

A)  supermassive black holes 
B)  galaxies 
C)  globular clusters 
D)  field stars 
A)  supermassive black holes 
B)  galaxies 
C)  globular clusters 
D)  field stars

Question 8

M87 is a giant elliptical radio galaxy.Its radio emission is primarily from the:

Accepted Answer

A)  galactic nucleus. 
B)  lobes outside the galaxy. 
C)  jet leading from the nucleus to the lobes. 
D)  entire galaxy, including the jet and the lobes. 
A)  galactic nucleus. 
B)  lobes outside the galaxy. 
C)  jet leading from the nucleus to the lobes. 
D)  entire galaxy, including the jet and the lobes.

Question 9

What is an Einstein ring?

Accepted Answer

A)  an arc of relativistic particles ejected from a galactic nucleus 
B)  an example of the image formed by a gravitational lens 
C)  a ring of material in some spiral galaxies created by a collision with a smaller galaxy 
D)  an accretion disk around a black hole 
A)  an arc of relativistic particles ejected from a galactic nucleus 
B)  an example of the image formed by a gravitational lens 
C)  a ring of material in some spiral galaxies created by a collision with a smaller galaxy 
D)  an accretion disk around a black hole

Question 10

What happens in the bar of a barred spiral?

Accepted Answer

A)  The bar rotates like a rigid body with no relative motion of the stars and gas inside. 
B)  The bar is part of the spiral arm structure, and it is actually a shock wave moving through the relatively rapid circular motion of the individual stars. 
C)  Stars tend to enter one end of the bar, pass through the it, and exit at the other end. 
D)  Stars and gas tend to move back and forth from one end of the bar to the other. 
A)  The bar rotates like a rigid body with no relative motion of the stars and gas inside. 
B)  The bar is part of the spiral arm structure, and it is actually a shock wave moving through the relatively rapid circular motion of the individual stars. 
C)  Stars tend to enter one end of the bar, pass through the it, and exit at the other end. 
D)  Stars and gas tend to move back and forth from one end of the bar to the other.

Question 11

An astronomer studying a cluster of galaxies finds a galaxy that is round and has a disk and central bulge like a spiral galaxy but has no spiral arms.How should the astronomer classify this galaxy?

Accepted Answer

A)  E0 
B)  E7 
C)  Sa 
D)  S0 
A)  E0 
B)  E7 
C)  Sa 
D)  S0

Question 12

In discussing galaxies and the universe,astronomers often talk about "voids." What are voids?

Accepted Answer

A)  large expanses of space between galaxies where there is essentially no gas or dust 
B)  holes in some galaxies where a collision by another, smaller galaxy has removed the dust, gas, and stars in that region 
C)  volumes of space hundreds of millions of light-years across that contain almost no galaxies 
D)  regions in clusters of galaxies that seem to be devoid of matter 
A)  large expanses of space between galaxies where there is essentially no gas or dust 
B)  holes in some galaxies where a collision by another, smaller galaxy has removed the dust, gas, and stars in that region 
C)  volumes of space hundreds of millions of light-years across that contain almost no galaxies 
D)  regions in clusters of galaxies that seem to be devoid of matter

Question 13

Lenticular galaxies,S0,have no spiral arms.What is the difference between an S0 and an elliptical E0,which also has no spiral arms?

Accepted Answer

A)  There is no difference. These are two different designations for the same thing. 
B)  An S0 will have more gas and dust than an E0. 
C)  The S0 will contain primarily Population II stars, while the E0 has primarily Population I stars. 
D)  The S0 will be likely to contain supernova remnants, while ellipticals never contain supernova remnants. 
A)  There is no difference. These are two different designations for the same thing. 
B)  An S0 will have more gas and dust than an E0. 
C)  The S0 will contain primarily Population II stars, while the E0 has primarily Population I stars. 
D)  The S0 will be likely to contain supernova remnants, while ellipticals never contain supernova remnants.

Question 14

Why is it that we will not see fluctuations in light output in times shorter than about 1 day when we observe an extragalactic source whose diameter is about 1 light-day?

Accepted Answer

A)  Absorption of light by intergalactic matter will smooth out rapid fluctuations within the beam. 
B)  The light from different parts of the source will be Doppler-shifted by different amounts, allowing us to see only an average shift. 
C)  It is inconceivable that a source of this size could vary on such short time scales. 
D)  Arrival times will be different from different parts of the source, which will smooth out short-term fluctuations. 
A)  Absorption of light by intergalactic matter will smooth out rapid fluctuations within the beam. 
B)  The light from different parts of the source will be Doppler-shifted by different amounts, allowing us to see only an average shift. 
C)  It is inconceivable that a source of this size could vary on such short time scales. 
D)  Arrival times will be different from different parts of the source, which will smooth out short-term fluctuations.

Question 15

The distance to the bright quasar 3C 273 is estimated to be:

Accepted Answer

A)  2 billion ly. 
B)  20,000 ly. 
C)  just beyond the Milky Way. 
D)  3 million ly. 
A)  2 billion ly. 
B)  20,000 ly. 
C)  just beyond the Milky Way. 
D)  3 million ly.

Question 16

Clusters of galaxies can be rich or poor,regular or irregular.But one thing they all have in common is that,if all galaxies could be detected,the majority of galaxies would be:

Accepted Answer

A)  normal spirals. 
B)  ellipticals. 
C)  irregulars. 
D)  barred spirals. 
A)  normal spirals. 
B)  ellipticals. 
C)  irregulars. 
D)  barred spirals.

Question 17

The Milky Way,the galaxy in which the Sun resides,is an example of which type of galaxy?

Accepted Answer

A)  spiral (a regular pattern of spiral arms) 
B)  elliptical (a smooth star distribution lacking spiral arms) 
C)  The Milky Way is not a galaxy at all but a large cluster of stars. 
D)  irregular (possible clumps of stars but no overall pattern) 
A)  spiral (a regular pattern of spiral arms) 
B)  elliptical (a smooth star distribution lacking spiral arms) 
C)  The Milky Way is not a galaxy at all but a large cluster of stars. 
D)  irregular (possible clumps of stars but no overall pattern)

Question 18

The surprising observational fact about quasars is that they appear to:

Accepted Answer

A)  produce the energy output of greater than 100 galaxies in a volume similar to that of our planetary system. 
B)  be the largest known structures in the universe, although they produce only modest amounts of energy. 
C)  be associated with ancient supernova explosions. 
D)  be moving rapidly toward us while emitting large amounts of energy. 
A)  produce the energy output of greater than 100 galaxies in a volume similar to that of our planetary system. 
B)  be the largest known structures in the universe, although they produce only modest amounts of energy. 
C)  be associated with ancient supernova explosions. 
D)  be moving rapidly toward us while emitting large amounts of energy.

Question 19

Synchrotron radiation,a type of nonthermal radiation,is found in the emission from:

Accepted Answer

A)  the nucleus of a Seyfert galaxy such as NGC 7742. 
B)  the nucleus of a giant elliptical radio galaxy such as M87. 
C)  the jet emanating from the giant elliptical radio galaxy M87. 
D)  radio lobes around Seyfert galaxies. 
A)  the nucleus of a Seyfert galaxy such as NGC 7742. 
B)  the nucleus of a giant elliptical radio galaxy such as M87. 
C)  the jet emanating from the giant elliptical radio galaxy M87. 
D)  radio lobes around Seyfert galaxies.

Question 20

What observations convince us that the energy source of a quasar is physically very small?

Accepted Answer

A)  rapid fluctuations in brightness since variations over 1 day mean that the source must be less than 1 light-day across 
B)  instant disappearance of the quasar when occulted by the Moon's edge as the Moon moves in front of a quasar, indicating a very small source size 
C)  sharpness of the emission lines in their optical spectra since motions within a large source would smear out the line shapes 
D)  extremely small size of the image of a quasar, even from Hubble Space Telescope images and radio interferometry measurements 
A)  rapid fluctuations in brightness since variations over 1 day mean that the source must be less than 1 light-day across 
B)  instant disappearance of the quasar when occulted by the Moon's edge as the Moon moves in front of a quasar, indicating a very small source size 
C)  sharpness of the emission lines in their optical spectra since motions within a large source would smear out the line shapes 
D)  extremely small size of the image of a quasar, even from Hubble Space Telescope images and radio interferometry measurements

Quasars are:

What is the present belief about the location of the Milky Way Galaxy?

The spectrum of a BL Lacertae object shows:

"Standard candles," which are important for finding distances to remote galaxies,are:

Which statement about clusters of galaxies is TRUE?

Who first discovered that many galaxies are moving away from Earth?

The halo of the Milky Way Galaxy consists of a number of objects that orbit the galactic center and periodically pass through the galactic plane.Which objects are NOT among the galactic halo objects?

M87 is a giant elliptical radio galaxy.Its radio emission is primarily from the:

What is an Einstein ring?

What happens in the bar of a barred spiral?

An astronomer studying a cluster of galaxies finds a galaxy that is round and has a disk and central bulge like a spiral galaxy but has no spiral arms.How should the astronomer classify this galaxy?

In discussing galaxies and the universe,astronomers often talk about "voids." What are voids?

Lenticular galaxies,S0,have no spiral arms.What is the difference between an S0 and an elliptical E0,which also has no spiral arms?

Why is it that we will not see fluctuations in light output in times shorter than about 1 day when we observe an extragalactic source whose diameter is about 1 light-day?

The distance to the bright quasar 3C 273 is estimated to be:

Clusters of galaxies can be rich or poor,regular or irregular.But one thing they all have in common is that,if all galaxies could be detected,the majority of galaxies would be:

The Milky Way,the galaxy in which the Sun resides,is an example of which type of galaxy?

The surprising observational fact about quasars is that they appear to:

Synchrotron radiation,a type of nonthermal radiation,is found in the emission from:

What observations convince us that the energy source of a quasar is physically very small?

Discovering the Night Sky

Gravitation and the Waltz of the Planets

Light and Telescopes

Formation of the Solar System and Other Planetary Systems

Exoplanets

The Terrestrial Planets and Their Moons

The Outer Planets and Their Moons

Vagabonds of the Solar System

The Sun: Our Extraordinary Ordinary Star

Characterizing Stars

The Lives of the Stars From Birth Through Middle Age

The Deaths and Remnants of Stars

Cosmology

Astrobiology

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Exam 13: The Galaxies

Quasars are:

What is the present belief about the location of the Milky Way Galaxy?

The spectrum of a BL Lacertae object shows:

"Standard candles," which are important for finding distances to remote galaxies,are:

Which statement about clusters of galaxies is TRUE?

Who first discovered that many galaxies are moving away from Earth?

The halo of the Milky Way Galaxy consists of a number of objects that orbit the galactic center and periodically pass through the galactic plane.Which objects are NOT among the galactic halo objects?

M87 is a giant elliptical radio galaxy.Its radio emission is primarily from the:

What is an Einstein ring?

What happens in the bar of a barred spiral?

An astronomer studying a cluster of galaxies finds a galaxy that is round and has a disk and central bulge like a spiral galaxy but has no spiral arms.How should the astronomer classify this galaxy?

In discussing galaxies and the universe,astronomers often talk about "voids." What are voids?

Lenticular galaxies,S0,have no spiral arms.What is the difference between an S0 and an elliptical E0,which also has no spiral arms?

Why is it that we will not see fluctuations in light output in times shorter than about 1 day when we observe an extragalactic source whose diameter is about 1 light-day?

The distance to the bright quasar 3C 273 is estimated to be:

Clusters of galaxies can be rich or poor,regular or irregular.But one thing they all have in common is that,if all galaxies could be detected,the majority of galaxies would be:

The Milky Way,the galaxy in which the Sun resides,is an example of which type of galaxy?

The surprising observational fact about quasars is that they appear to:

Synchrotron radiation,a type of nonthermal radiation,is found in the emission from:

What observations convince us that the energy source of a quasar is physically very small?

Discovering the Night Sky

Gravitation and the Waltz of the Planets

Light and Telescopes

Formation of the Solar System and Other Planetary Systems

Exoplanets

The Terrestrial Planets and Their Moons

The Outer Planets and Their Moons

Vagabonds of the Solar System

The Sun: Our Extraordinary Ordinary Star

Characterizing Stars

The Lives of the Stars From Birth Through Middle Age

The Deaths and Remnants of Stars

Cosmology

Astrobiology

Filters