Question 1

Quasars:

Accepted Answer

A)  are more common in nearby clusters of galaxies and less common in distant clusters of galaxies. 
B)  are rare in the Local Group, with only one or two examples. 
C)  increase in number as redshift increases, a relationship that persists to the highest redshifts we can measure. 
D)  peaked in number about 2 billion years after the Big Bang. 
A)  are more common in nearby clusters of galaxies and less common in distant clusters of galaxies. 
B)  are rare in the Local Group, with only one or two examples. 
C)  increase in number as redshift increases, a relationship that persists to the highest redshifts we can measure. 
D)  peaked in number about 2 billion years after the Big Bang.

Question 2

Much of the mass in galaxies and clusters of galaxies is dark matter.All of the techniques below are means of detecting evidence of this dark matter EXCEPT ONE.Which is the exception?

Accepted Answer

A)  measuring the speed of stars in their orbits around a galactic center 
B)  gravitational lensing of very distant galaxies by a nearby galaxy (or cluster) and its accompanying dark matter 
C)  observing the aftermath of a collision such as that in galaxy cluster 1E0657-56 
D)  observing X rays being emitted from the space between galaxies in rich clusters 
A)  measuring the speed of stars in their orbits around a galactic center 
B)  gravitational lensing of very distant galaxies by a nearby galaxy (or cluster) and its accompanying dark matter 
C)  observing the aftermath of a collision such as that in galaxy cluster 1E0657-56 
D)  observing X rays being emitted from the space between galaxies in rich clusters

Question 3

Which object is NOT classified as an active galaxy?

Accepted Answer

A)  a Seyfert galaxy 
B)  a BL Lacertae object 
C)  a quasar 
D)  a barred spiral 
A)  a Seyfert galaxy 
B)  a BL Lacertae object 
C)  a quasar 
D)  a barred spiral

Question 4

Overall,through space,galaxies are:

Accepted Answer

A)  distributed uniformly, out to the farthest distances. 
B)  clustered together in several high-density centers with very little matter linking them together. 
C)  concentrated around one position in space, presumably the original site of the Big Bang. 
D)  concentrated on the surface of huge open spaces or voids, like soap bubbles. 
A)  distributed uniformly, out to the farthest distances. 
B)  clustered together in several high-density centers with very little matter linking them together. 
C)  concentrated around one position in space, presumably the original site of the Big Bang. 
D)  concentrated on the surface of huge open spaces or voids, like soap bubbles.

Question 5

The possible presence of a supermassive black hole at the center of the Milky Way Galaxy has been deduced from:

Accepted Answer

A)  gravitational radiation emitted by stars as they are swallowed by the black hole. 
B)  powerful magnetic fields in the huge filaments arching away from (or toward) the center. 
C)  the number of globular clusters that concentrate toward the galactic center. 
D)  the very high orbital speed of ionized gas clouds close to the galactic center. 
A)  gravitational radiation emitted by stars as they are swallowed by the black hole. 
B)  powerful magnetic fields in the huge filaments arching away from (or toward) the center. 
C)  the number of globular clusters that concentrate toward the galactic center. 
D)  the very high orbital speed of ionized gas clouds close to the galactic center.

Question 6

Which kind of stars are the major source of energy for the heating of the dust clouds and the H II emission nebulae in the planes of the Milky Way and other galaxies?

Accepted Answer

A)  hot, young O and B stars, via their UV radiation 
B)  numerous old red giant K and M stars, via their IR heat radiation 
C)  very hot white dwarf stars, the remnants of planetary nebulae in the gas clouds 
D)  many nova and supernova explosions of stars within the gas and dust clouds 
A)  hot, young O and B stars, via their UV radiation 
B)  numerous old red giant K and M stars, via their IR heat radiation 
C)  very hot white dwarf stars, the remnants of planetary nebulae in the gas clouds 
D)  many nova and supernova explosions of stars within the gas and dust clouds

Question 7

In which category of galaxy do we find the largest galaxies in the universe?

Accepted Answer

A)  lenticular 
B)  large spiral, like the Milky Way 
C)  irregular 
D)  elliptical 
A)  lenticular 
B)  large spiral, like the Milky Way 
C)  irregular 
D)  elliptical

Question 8

The diameter of the Milky Way Galaxy is about;

Accepted Answer

A)  100 kpc. 
B)  31 kpc. 
C)  3.1 kpc. 
D)  2 kpc. 
A)  100 kpc. 
B)  31 kpc. 
C)  3.1 kpc. 
D)  2 kpc.

Question 9

How has the number of quasars varied over the history of the universe?

Accepted Answer

A)  The number of quasars has remained approximately constant over time, with new quasars being formed to replace those which deplete their fuel and die out. 
B)  Quasars were much more numerous 11 or 12 billion years ago, but since then the supermassive black holes in their centers have depleted their available gas and dust and their accretion disks have disappeared and they are no longer quasars. 
C)  It takes billions of years to accumulate enough material to form a supermassive black hole, the heart of a quasar. Thus, the number of quasars has grown steadily as more and more supermassive black holes are formed. 
D)  The number of quasars has decreased steadily as they have evolved into other types of AGN like radio galaxies and BL Lacertae objects. 
A)  The number of quasars has remained approximately constant over time, with new quasars being formed to replace those which deplete their fuel and die out. 
B)  Quasars were much more numerous 11 or 12 billion years ago, but since then the supermassive black holes in their centers have depleted their available gas and dust and their accretion disks have disappeared and they are no longer quasars. 
C)  It takes billions of years to accumulate enough material to form a supermassive black hole, the heart of a quasar. Thus, the number of quasars has grown steadily as more and more supermassive black holes are formed. 
D)  The number of quasars has decreased steadily as they have evolved into other types of AGN like radio galaxies and BL Lacertae objects.

Question 10

A classical Cepheid variable star is seen to vary regularly with a period of 25 days.How many times brighter than the Sun would this star appear to be if it were to replace the Sun in our solar system? (See Figure 13-3 of Comins,Discovering the Essential Universe,6th ed.)

Accepted Answer

A)  1000 
B)  4 
C)  10,000 
D)  10² 
A)  1000 
B)  4 
C)  10,000 
D)  10²

Question 11

What mechanism appears to produce the double-radio sources seen in intergalactic space?

Accepted Answer

A)  two oppositely directed jets of matter, ejected from a small source 
B)  two radio galaxies orbiting each other much like two binary stars 
C)  a radio-bright galaxy with a dark absorbing disk edge-on to Earth, splitting the source into two as seen from Earth 
D)  two black holes orbiting around a small but massive galactic nucleus 
A)  two oppositely directed jets of matter, ejected from a small source 
B)  two radio galaxies orbiting each other much like two binary stars 
C)  a radio-bright galaxy with a dark absorbing disk edge-on to Earth, splitting the source into two as seen from Earth 
D)  two black holes orbiting around a small but massive galactic nucleus

Question 12

The Hubble classification description for an S0 galaxy is a:

Accepted Answer

A)  small central bulge with loosely wound spiral arms. 
B)  disk and central bulge with a smooth light distribution and no spiral arms. 
C)  large central bulge with tightly wound spiral arms. 
D)  round or spherical shape with a smooth light distribution and no disk or central bulge. 
A)  small central bulge with loosely wound spiral arms. 
B)  disk and central bulge with a smooth light distribution and no spiral arms. 
C)  large central bulge with tightly wound spiral arms. 
D)  round or spherical shape with a smooth light distribution and no disk or central bulge.

Question 13

What recent evidence seems to indicate that several nearby galaxies may contain supermassive black holes at their centers?

Accepted Answer

A)  The rotation curve of these galaxies shows no decrease in orbital velocity of stars as the radius of orbit increases out to the observable limit of the galaxy, indicating an unusual source of gravity. 
B)  Spectroscopic observations of stars near the centers of these galaxies show extremely fast orbital velocities, indicating the presence of a large mass to keep stars in orbit. 
C)  Extreme redshift of light from stars near the centers of these galaxies is caused by gravitational redshift from a very massive object. 
D)  These galaxies are rushing rapidly toward each other (and in at least one case, toward the Milky Way!) because of the gravitational attraction among them. 
A)  The rotation curve of these galaxies shows no decrease in orbital velocity of stars as the radius of orbit increases out to the observable limit of the galaxy, indicating an unusual source of gravity. 
B)  Spectroscopic observations of stars near the centers of these galaxies show extremely fast orbital velocities, indicating the presence of a large mass to keep stars in orbit. 
C)  Extreme redshift of light from stars near the centers of these galaxies is caused by gravitational redshift from a very massive object. 
D)  These galaxies are rushing rapidly toward each other (and in at least one case, toward the Milky Way!) because of the gravitational attraction among them.

Question 14

The Milky Way Galaxy is NOT orbited by:

Accepted Answer

A)  globular clusters. 
B)  dwarf elliptical galaxies. 
C)  the Magellanic Clouds. 
D)  individual (field) stars. 
A)  globular clusters. 
B)  dwarf elliptical galaxies. 
C)  the Magellanic Clouds. 
D)  individual (field) stars.

Question 15

The intrinsic brightness (represented by luminosity)of a Cepheid variable star compared with that of the Sun is:

Accepted Answer

A)  generally between 10 and 100 times larger. 
B)  about the same. 
C)  significantly less. 
D)  several hundred to several thousand times larger. 
A)  generally between 10 and 100 times larger. 
B)  about the same. 
C)  significantly less. 
D)  several hundred to several thousand times larger.

Question 16

Which observations of the radiation from quasars indicate that quasars are physically very small objects compared with galaxies?

Accepted Answer

A)  their emission, which is mostly in the infrared and radio range 
B)  their starlike appearance on photographs, showing no structure 
C)  rapid fluctuations in output, often in less than 1 day 
D)  very high redshift of their light 
A)  their emission, which is mostly in the infrared and radio range 
B)  their starlike appearance on photographs, showing no structure 
C)  rapid fluctuations in output, often in less than 1 day 
D)  very high redshift of their light

Question 17

What is the typical temperature of the intergalactic gas in rich clusters of galaxies?

Accepted Answer

A)  10,000 to 20,000 K 
B)  1 to 10 billion K 
C)  10 to 100 K 
D)  10 to 100 million K 
A)  10,000 to 20,000 K 
B)  1 to 10 billion K 
C)  10 to 100 K 
D)  10 to 100 million K

Question 18

The Andromeda Galaxy (M31)is BEST described as a(n):

Accepted Answer

A)  spiral collection of stars, dust, and gas 200,000 ly across. 
B)  extension of the Milky Way. 
C)  vortex surrounding a black hole. 
D)  gaseous nebula extending for 6° across Earth's sky. 
A)  spiral collection of stars, dust, and gas 200,000 ly across. 
B)  extension of the Milky Way. 
C)  vortex surrounding a black hole. 
D)  gaseous nebula extending for 6° across Earth's sky.

Question 19

If the Sun were to be at or close to the galactic center of the Milky Way,the intensity of starlight in the nighttime sky on Earth would be:

Accepted Answer

A)  very much fainter than at present because neighboring stars would be obscured by dense dust and gas clouds. 
B)  about the same as it is now since neighboring stars would still be relatively far away. 
C)  about twice as bright as at present since neighboring stars would be mostly bright, young blue stars in about the same numbers as the present, older, and less bright red giant neighbors to the Sun. 
D)  extremely intense from the dense field of stars, equivalent to about 200 full Moons. 
A)  very much fainter than at present because neighboring stars would be obscured by dense dust and gas clouds. 
B)  about the same as it is now since neighboring stars would still be relatively far away. 
C)  about twice as bright as at present since neighboring stars would be mostly bright, young blue stars in about the same numbers as the present, older, and less bright red giant neighbors to the Sun. 
D)  extremely intense from the dense field of stars, equivalent to about 200 full Moons.

Question 20

The typical diameter of a spiral galaxy is about:

Accepted Answer

A)  10⁷ ly. 
B)  10⁵ ly. 
C)  1 ly. 
D)  100 ly. 
A)  10⁷ ly. 
B)  10⁵ ly. 
C)  1 ly. 
D)  100 ly.

Quasars:

Much of the mass in galaxies and clusters of galaxies is dark matter.All of the techniques below are means of detecting evidence of this dark matter EXCEPT ONE.Which is the exception?

Which object is NOT classified as an active galaxy?

Overall,through space,galaxies are:

The possible presence of a supermassive black hole at the center of the Milky Way Galaxy has been deduced from:

Which kind of stars are the major source of energy for the heating of the dust clouds and the H II emission nebulae in the planes of the Milky Way and other galaxies?

In which category of galaxy do we find the largest galaxies in the universe?

The diameter of the Milky Way Galaxy is about;

How has the number of quasars varied over the history of the universe?

A classical Cepheid variable star is seen to vary regularly with a period of 25 days.How many times brighter than the Sun would this star appear to be if it were to replace the Sun in our solar system? (See Figure 13-3 of Comins,Discovering the Essential Universe,6th ed.)

What mechanism appears to produce the double-radio sources seen in intergalactic space?

The Hubble classification description for an S0 galaxy is a:

What recent evidence seems to indicate that several nearby galaxies may contain supermassive black holes at their centers?

The Milky Way Galaxy is NOT orbited by:

The intrinsic brightness (represented by luminosity)of a Cepheid variable star compared with that of the Sun is:

Which observations of the radiation from quasars indicate that quasars are physically very small objects compared with galaxies?

What is the typical temperature of the intergalactic gas in rich clusters of galaxies?

The Andromeda Galaxy (M31)is BEST described as a(n):

If the Sun were to be at or close to the galactic center of the Milky Way,the intensity of starlight in the nighttime sky on Earth would be:

The typical diameter of a spiral galaxy is about:

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

Quasars:

Much of the mass in galaxies and clusters of galaxies is dark matter.All of the techniques below are means of detecting evidence of this dark matter EXCEPT ONE.Which is the exception?

Which object is NOT classified as an active galaxy?

Overall,through space,galaxies are:

The possible presence of a supermassive black hole at the center of the Milky Way Galaxy has been deduced from:

Which kind of stars are the major source of energy for the heating of the dust clouds and the H II emission nebulae in the planes of the Milky Way and other galaxies?

In which category of galaxy do we find the largest galaxies in the universe?

The diameter of the Milky Way Galaxy is about;

How has the number of quasars varied over the history of the universe?

A classical Cepheid variable star is seen to vary regularly with a period of 25 days.How many times brighter than the Sun would this star appear to be if it were to replace the Sun in our solar system? (See Figure 13-3 of Comins,Discovering the Essential Universe,6th ed.)

What mechanism appears to produce the double-radio sources seen in intergalactic space?

The Hubble classification description for an S0 galaxy is a:

What recent evidence seems to indicate that several nearby galaxies may contain supermassive black holes at their centers?

The Milky Way Galaxy is NOT orbited by:

The intrinsic brightness (represented by luminosity)of a Cepheid variable star compared with that of the Sun is:

Which observations of the radiation from quasars indicate that quasars are physically very small objects compared with galaxies?

What is the typical temperature of the intergalactic gas in rich clusters of galaxies?

The Andromeda Galaxy (M31)is BEST described as a(n):

If the Sun were to be at or close to the galactic center of the Milky Way,the intensity of starlight in the nighttime sky on Earth would be:

The typical diameter of a spiral galaxy is about:

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