Question 1

One of the big puzzles about the properties and behavior of large clusters of galaxies is that:

Accepted Answer

A)  each cluster appears to consist of the same type of galaxy, some made up totally of spiral galaxies while others contain only ellipticals. 
B)  they appear to be spread uniformly throughout space in all directions, which is difficult to explain with the Big Bang theory. 
C)  there appears to be insufficient mass in the luminous matter (stars, and so on) to hold the cluster together gravitationally. 
D)  they appear not to take part in the general expansion of the universe, in contrast to single separate galaxies, probably because they are gravitationally bound to one another. 
A)  each cluster appears to consist of the same type of galaxy, some made up totally of spiral galaxies while others contain only ellipticals. 
B)  they appear to be spread uniformly throughout space in all directions, which is difficult to explain with the Big Bang theory. 
C)  there appears to be insufficient mass in the luminous matter (stars, and so on) to hold the cluster together gravitationally. 
D)  they appear not to take part in the general expansion of the universe, in contrast to single separate galaxies, probably because they are gravitationally bound to one another.

Question 2

Which is a characteristic of a Seyfert galaxy?

Accepted Answer

A)  A Seyfert galaxy has no spiral arms. 
B)  The nucleus of a Seyfert galaxy is unusually bright compared with the spiral arms. 
C)  The nucleus of a Seyfert galaxy is unusually faint compared with the spiral arms. 
D)  The spectrum of a Seyfert galaxy shows particularly narrow absorption lines. 
A)  A Seyfert galaxy has no spiral arms. 
B)  The nucleus of a Seyfert galaxy is unusually bright compared with the spiral arms. 
C)  The nucleus of a Seyfert galaxy is unusually faint compared with the spiral arms. 
D)  The spectrum of a Seyfert galaxy shows particularly narrow absorption lines.

Question 3

The relationship between a galaxy and the galaxy cluster of which it is a part is similar to the relationship between a galaxy cluster and the supercluster of which it is a part,with one important difference.What is that difference?

Accepted Answer

A)  Clusters contain only like galaxies (spirals, etc.); superclusters combine clusters of various types. 
B)  Superclusters rely on copious amounts of dark matter to bind them together; clusters do not. 
C)  A cluster is a gravitationally bound system; a supercluster is not. 
D)  The galaxy clusters in a supercluster orbit an enormous black hole; this is not the case with the galaxies in a cluster. 
A)  Clusters contain only like galaxies (spirals, etc.); superclusters combine clusters of various types. 
B)  Superclusters rely on copious amounts of dark matter to bind them together; clusters do not. 
C)  A cluster is a gravitationally bound system; a supercluster is not. 
D)  The galaxy clusters in a supercluster orbit an enormous black hole; this is not the case with the galaxies in a cluster.

Question 4

The biggest and intrinsically brightest galaxies in the universe are members of which group?

Accepted Answer

A)  irregular galaxies 
B)  barred spirals 
C)  large spirals 
D)  ellipticals 
A)  irregular galaxies 
B)  barred spirals 
C)  large spirals 
D)  ellipticals

Question 5

The Hubble law,representing observations of distant objects in the universe,relates which two parameters?

Accepted Answer

A)  distance to a distant object and the redshift of its light 
B)  mass of an object and its luminosity 
C)  luminosity and position of stars in the galaxy 
D)  mass of a distant object and its recession velocity 
A)  distance to a distant object and the redshift of its light 
B)  mass of an object and its luminosity 
C)  luminosity and position of stars in the galaxy 
D)  mass of a distant object and its recession velocity

Question 6

According to the theory of self-propagating star formation,the spiral arms of flocculent spiral galaxies are broad and poorly designed because:

Accepted Answer

A)  the spiral arms in these galaxies are strongly influenced by the black hole at the center of the galaxy. 
B)  the density wave has been disrupted by the bar across the center of the galaxy. 
C)  dust lanes occur in broad bands rather than in the narrow bands found in grand-design spirals. 
D)  the spiral arm segments are defined only by the relatively short-lived O and B type stars. 
A)  the spiral arms in these galaxies are strongly influenced by the black hole at the center of the galaxy. 
B)  the density wave has been disrupted by the bar across the center of the galaxy. 
C)  dust lanes occur in broad bands rather than in the narrow bands found in grand-design spirals. 
D)  the spiral arm segments are defined only by the relatively short-lived O and B type stars.

Question 7

What fraction of the mass of the Milky Way Galaxy is in a form that we have been able to see?

Accepted Answer

A)  about 50% 
B)  100%-who ever heard of matter that can't be seen? 
C)  about 10% 
D)  about 90% 
A)  about 50% 
B)  100%-who ever heard of matter that can't be seen? 
C)  about 10% 
D)  about 90%

Question 8

What is the Hubble classification for a spiral galaxy with a large nuclear region and tightly wound arms?

Accepted Answer

A)  Sb 
B)  SBc 
C)  Sc 
D)  Sa 
A)  Sb 
B)  SBc 
C)  Sc 
D)  Sa

Question 9

According to the Hubble classification scheme,an E6 galaxy:

Accepted Answer

A)  has more tightly wound spiral arms than an E2 galaxy. 
B)  has a shorter central bar in its disk than an E2 galaxy. 
C)  is rounder looking than an E2 galaxy. 
D)  is more elongated than an E2 galaxy. 
A)  has more tightly wound spiral arms than an E2 galaxy. 
B)  has a shorter central bar in its disk than an E2 galaxy. 
C)  is rounder looking than an E2 galaxy. 
D)  is more elongated than an E2 galaxy.

Question 10

What do we know about the geometry of the "dark matter" distribution in the vicinity of the Milky Way Galaxy?

Accepted Answer

A)  The dark matter appears to be a lens-shaped disk like the Galaxy's disk of visible stars, only larger. 
B)  The dark matter appears to be a spherical halo. 
C)  Dark matter, including that near the Milky Way Galaxy, appears to be part of a uniform density distribution that fills all space. 
D)  The geometry of the dark matter distribution, like its constituents, is totally unknown at the present time. 
A)  The dark matter appears to be a lens-shaped disk like the Galaxy's disk of visible stars, only larger. 
B)  The dark matter appears to be a spherical halo. 
C)  Dark matter, including that near the Milky Way Galaxy, appears to be part of a uniform density distribution that fills all space. 
D)  The geometry of the dark matter distribution, like its constituents, is totally unknown at the present time.

Question 11

What does a spiral galaxy look like when seen edge-on?

Accepted Answer

A)  a thick, straight line of light with a central light bulge 
B)  circular, with no evidence of spiral arms since they are hidden by dust and gas 
C)  a thick line curved into a spiral shape 
D)  a thick, straight line with constant thickness 
A)  a thick, straight line of light with a central light bulge 
B)  circular, with no evidence of spiral arms since they are hidden by dust and gas 
C)  a thick line curved into a spiral shape 
D)  a thick, straight line with constant thickness

Question 12

What mechanism is believed to produce grand-design spiral galaxies?

Accepted Answer

A)  shock waves from explosive star formation in the nuclear bulge 
B)  density waves in the interstellar medium 
C)  satellite galaxies plunging through the disk of the nuclear spiral galaxy 
D)  self-propagating star formation, where star formation occurs in bursts 
A)  shock waves from explosive star formation in the nuclear bulge 
B)  density waves in the interstellar medium 
C)  satellite galaxies plunging through the disk of the nuclear spiral galaxy 
D)  self-propagating star formation, where star formation occurs in bursts

Question 13

If interstellar dust obscures our view of distant regions of space at optical wavelengths,which statement is TRUE?

Accepted Answer

A)  The obscuration is very clumpy and random over the whole sky; the individual absorbing dust clouds show no preference for one particular direction or plane. 
B)  The obscuration is roughly uniform over the whole sky. 
C)  The obscuration is the least in the plane of the Milky Way Galaxy and is strongest when we look out into the galactic halo, at right angles in this plane. 
D)  The obscuration is severe only in the plane of the Milky Way Galaxy. 
A)  The obscuration is very clumpy and random over the whole sky; the individual absorbing dust clouds show no preference for one particular direction or plane. 
B)  The obscuration is roughly uniform over the whole sky. 
C)  The obscuration is the least in the plane of the Milky Way Galaxy and is strongest when we look out into the galactic halo, at right angles in this plane. 
D)  The obscuration is severe only in the plane of the Milky Way Galaxy.

Question 14

Which single major problem perhaps puzzles astronomers the MOST as they attempt to interpret the properties and behavior of clusters of galaxies?

Accepted Answer

A)  the rate of supernova occurrence in galaxies in some clusters 
B)  the missing-mass problem, where the amount of mass needed for galactic cluster stability is estimated to be at least 10 times more than the observed visible mass 
C)  the presence of star formation in many galaxies long after it is expected to have died out 
D)  the structure and motion of spiral arms in galaxies in many clusters 
A)  the rate of supernova occurrence in galaxies in some clusters 
B)  the missing-mass problem, where the amount of mass needed for galactic cluster stability is estimated to be at least 10 times more than the observed visible mass 
C)  the presence of star formation in many galaxies long after it is expected to have died out 
D)  the structure and motion of spiral arms in galaxies in many clusters

Question 15

Seyfert galaxies are a distinct class of galaxies because they:

Accepted Answer

A)  are very close to the Milky Way and appear to be gravitationally bound to it. 
B)  have very bright, very hot, starlike central cores with variable energy output. 
C)  are completely devoid of structure, appearing to be amorphous spheres of gas and dust. 
D)  are in the constellation of Seyfert in Earth's southern hemisphere sky. 
A)  are very close to the Milky Way and appear to be gravitationally bound to it. 
B)  have very bright, very hot, starlike central cores with variable energy output. 
C)  are completely devoid of structure, appearing to be amorphous spheres of gas and dust. 
D)  are in the constellation of Seyfert in Earth's southern hemisphere sky.

Question 16

The idea that some of the "nebulae" that are observed in the sky might be "island universes," immense collections of stars far beyond the Milky Way,was first proposed by:

Accepted Answer

A)  Immanuel Kant in 1755. 
B)  Albert Einstein in 1909. 
C)  Heber Curtis in 1920. 
D)  Lord Rosse in 1845. 
A)  Immanuel Kant in 1755. 
B)  Albert Einstein in 1909. 
C)  Heber Curtis in 1920. 
D)  Lord Rosse in 1845.

Question 17

What method is used to determine the distances of very remote galaxies?

Accepted Answer

A)  measurement of the apparent magnitudes of Type Ia supernovae in the galaxies 
B)  comparison of the apparent and absolute magnitudes of the galaxies 
C)  measurement of the apparent brightness and period of Cepheid variable stars in the galaxies 
D)  measurement of the angular size of a galaxy and an assumption about the actual physical size of the galaxy 
A)  measurement of the apparent magnitudes of Type Ia supernovae in the galaxies 
B)  comparison of the apparent and absolute magnitudes of the galaxies 
C)  measurement of the apparent brightness and period of Cepheid variable stars in the galaxies 
D)  measurement of the angular size of a galaxy and an assumption about the actual physical size of the galaxy

Question 18

What is it that makes the study of the structure of the Milky Way Galaxy more difficult than that of much more distant spiral galaxies?

Accepted Answer

A)  The galactic center is visible only from the southern hemisphere, where, until recently, no major telescopes were available for the study of galactic structure. 
B)  The Milky Way appears to be unique, with a structure quite unlike any other galaxy. 
C)  The Sun is within the Galaxy, and its motion confuses the interpretation of the motion of other parts of the Galaxy. 
D)  Most of the Milky Way is hidden behind dense gas and dust clouds in the galactic plane. 
A)  The galactic center is visible only from the southern hemisphere, where, until recently, no major telescopes were available for the study of galactic structure. 
B)  The Milky Way appears to be unique, with a structure quite unlike any other galaxy. 
C)  The Sun is within the Galaxy, and its motion confuses the interpretation of the motion of other parts of the Galaxy. 
D)  Most of the Milky Way is hidden behind dense gas and dust clouds in the galactic plane.

Question 19

Grand-design spiral galaxies:

Accepted Answer

A)  have a central bulge that does not rotate. 
B)  are encompassed within a large lens-shaped disk of dark matter. 
C)  are orbited by globular clusters that also exhibit star formation. 
D)  are most often near a companion galaxy. 
A)  have a central bulge that does not rotate. 
B)  are encompassed within a large lens-shaped disk of dark matter. 
C)  are orbited by globular clusters that also exhibit star formation. 
D)  are most often near a companion galaxy.

Question 20

What is the dominant radiation from the intergalactic matter in rich clusters of galaxies?

Accepted Answer

A)  ultraviolet light from electrons spiraling in magnetic fields 
B)  infrared radiation from dust 
C)  X rays from very hot gas 
D)  21-cm radio radiation from cool, neutral hydrogen gas 
A)  ultraviolet light from electrons spiraling in magnetic fields 
B)  infrared radiation from dust 
C)  X rays from very hot gas 
D)  21-cm radio radiation from cool, neutral hydrogen gas

One of the big puzzles about the properties and behavior of large clusters of galaxies is that:

Which is a characteristic of a Seyfert galaxy?

The relationship between a galaxy and the galaxy cluster of which it is a part is similar to the relationship between a galaxy cluster and the supercluster of which it is a part,with one important difference.What is that difference?

The biggest and intrinsically brightest galaxies in the universe are members of which group?

The Hubble law,representing observations of distant objects in the universe,relates which two parameters?

According to the theory of self-propagating star formation,the spiral arms of flocculent spiral galaxies are broad and poorly designed because:

What fraction of the mass of the Milky Way Galaxy is in a form that we have been able to see?

What is the Hubble classification for a spiral galaxy with a large nuclear region and tightly wound arms?

According to the Hubble classification scheme,an E6 galaxy:

What do we know about the geometry of the "dark matter" distribution in the vicinity of the Milky Way Galaxy?

What does a spiral galaxy look like when seen edge-on?

What mechanism is believed to produce grand-design spiral galaxies?

If interstellar dust obscures our view of distant regions of space at optical wavelengths,which statement is TRUE?

Which single major problem perhaps puzzles astronomers the MOST as they attempt to interpret the properties and behavior of clusters of galaxies?

Seyfert galaxies are a distinct class of galaxies because they:

The idea that some of the "nebulae" that are observed in the sky might be "island universes," immense collections of stars far beyond the Milky Way,was first proposed by:

What method is used to determine the distances of very remote galaxies?

What is it that makes the study of the structure of the Milky Way Galaxy more difficult than that of much more distant spiral galaxies?

Grand-design spiral galaxies:

What is the dominant radiation from the intergalactic matter in rich clusters of galaxies?

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

Exam 13: The Galaxies

One of the big puzzles about the properties and behavior of large clusters of galaxies is that:

Which is a characteristic of a Seyfert galaxy?

The relationship between a galaxy and the galaxy cluster of which it is a part is similar to the relationship between a galaxy cluster and the supercluster of which it is a part,with one important difference.What is that difference?

The biggest and intrinsically brightest galaxies in the universe are members of which group?

The Hubble law,representing observations of distant objects in the universe,relates which two parameters?

According to the theory of self-propagating star formation,the spiral arms of flocculent spiral galaxies are broad and poorly designed because:

What fraction of the mass of the Milky Way Galaxy is in a form that we have been able to see?

What is the Hubble classification for a spiral galaxy with a large nuclear region and tightly wound arms?

According to the Hubble classification scheme,an E6 galaxy:

What do we know about the geometry of the "dark matter" distribution in the vicinity of the Milky Way Galaxy?

What does a spiral galaxy look like when seen edge-on?

What mechanism is believed to produce grand-design spiral galaxies?

If interstellar dust obscures our view of distant regions of space at optical wavelengths,which statement is TRUE?

Which single major problem perhaps puzzles astronomers the MOST as they attempt to interpret the properties and behavior of clusters of galaxies?

Seyfert galaxies are a distinct class of galaxies because they:

The idea that some of the "nebulae" that are observed in the sky might be "island universes," immense collections of stars far beyond the Milky Way,was first proposed by:

What method is used to determine the distances of very remote galaxies?

What is it that makes the study of the structure of the Milky Way Galaxy more difficult than that of much more distant spiral galaxies?

Grand-design spiral galaxies:

What is the dominant radiation from the intergalactic matter in rich clusters of galaxies?

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