Deck 16: Normal and Active Galaxies: Building Blocks of the Universe

Question 1

The Virgo Cluster of galaxies is smaller than the Local Group.

Answer 1

False

Question 2

A Type Sa galaxy is a spiral with a large bulge and tightly wound arms.

Answer 2

True

Question 3

Most galaxies are spirals.

Answer 3

False

Question 4

On average, elliptical galaxies are richer star forming regions than spirals.

Question 5

As with our own Sun among the neighboring stars, most galaxies in the Local Group are smaller and dimmer than our own Milky Way.

Question 6

Irregular galaxies, although small, have large star- forming (HII) regions and much ongoing star formation for their size.

Question 7

The Milky Way is smaller than most members of the Local Group.

Question 8

The Virgo Cluster of galaxies is not much larger in size than the Local Group, but it does contain far more galaxies.

Question 9

Type Sc are the dustiest and flattest of the galaxies.

Question 10

In Hubble's "tuning fork," spirals are on the parallel branches.

Question 11

Compared to the spirals, elliptical galaxies tend to be more dusty.

Question 12

The most tightly wound spiral arms belong to Hubble's type Sa.

Question 13

Irregulars typically have very few blue stars.

Question 14

Irr II galaxies may be the result of a collision, or close encounter, of two normal galaxies.

Question 15

The Local Group of galaxies spans about 30 million light-years in diameter.

Question 16

Except for the Local Group, galaxies seem to be isolated and randomly in space.

Question 17

Among the ellipticals, E0 types look the most like huge globular star clusters.

Question 18

Unlike spirals, elliptical galaxies do not contain a flattened disk.

Question 19

Despite varying masses, all spiral galaxies look essentially the same.

Question 20

There are more giant elliptical than dwarf galaxies.

Question 21

Active galaxies emit most of their radiation as visible light.

Question 22

Space itself is expanding.

Question 23

While our Magellanic Clouds are irregulars, the companions to Andromeda are ellipticals.

Question 24

Quasars are the brightest objects in the universe.

Question 25

On average, active galaxies are rare and most are fairly distant from us.

Question 26

The Tully- Fisher relation allows us to determine the distance to the most distant galaxies.

Question 27

Seyfert galaxies are the only type that produces gravitational lensing.

Question 28

The central engine of an active galaxy is less than a parsec in diameter.

Question 29

Quasars appear to have very large redshifts, and are receding at nearly the speed of light.

Question 30

Hubble found a direct relation between a galaxy's velocity and distance.

Question 31

Virtually all galaxies are moving away from the Milky Way.

Question 32

In the Local Group, most members are either dwarf ellipticals or spirals.

Question 33

Quasars can emit thousands of times as much energy as normal galaxies.

Question 34

Emission nebula, such as M42, are much brighter than planetary nebulae, so are better suited for finding the distances to other galaxies.

Question 35

Core- dominated radio galaxies and radio galaxies with lobes are very similar in reality; we view them from different angles, which accounts for their different appearances.

Question 36

Radio galaxies emit only radio waves, and are not otherwise observable.

Question 37

M31 in Andromeda is a bigger version of our Galaxy, and the largest member of the Local Group.

Question 38

The closest other galaxy to our solar system is the Sagittarius Dwarf.

Question 39

When observing a quasar, we are probably looking at a stage of evolution in the very early universe.

Question 40

The additional energy given off by active galaxies is because of their higher stellar density.

Question 41

Synchrotron radiation is the major source of energy for active galaxies.

Question 42

There is evidence that a collision between a spiral and an elliptical galaxy has produced a radio galaxy.

Question 43

Nearby active galaxies, such as Centaurus A, are likely the mergers between colliding galaxies.

Question 44

A spherical galaxy, like M87, which looks like a monster globular cluster, is type

A) S0.
B) 0V.
C) ES1.
D) E0.
E) ES.

Question 45

The flattest of the ellipticals are class

A) E9.
B) SBO.
C) E0.
D) E7.
E) SBF.

Question 46

The lobes of radio galaxies are perpendicular to their plane of rotation.

Question 47

Centaurus A is the closest lobe radio galaxy, and may be a collision between a spiral and an elliptical galaxy.

Question 48

The light output from some quasars varies in just a few hours.

Question 49

Seyferts have properties that lie between quasars and normal spiral galaxies.

Question 50

The black hole in the core of a Seyfert galaxy consumes the equivalent of hundreds of solar masses a day.

Question 51

Quasars are far enough away that we must take the relativistic redshift into account when calculating their age.

Question 52

Seyferts are spirals with quasar- like nuclei.

Question 53

Seyferts are irregular galaxies with very strong radio emission.

Question 54

Which property is common to spiral galaxies?

A) globular clusters in the nucleus
B) ongoing star formation and emission nebula in the arms
C) open clusters in the halo
D) very little internal structure
E) ongoing star formation and emission nebula in the halo

Question 55

In this diagram, the galaxy at the left side is a(n)

A) barred spiral.
B) spiral.
C) Seyfert.
D) elliptical.
E) irregular.

Question 56

The supermassive black holes that may be powering active galaxies emit only synchrotron radiation.

Question 57

Centaurus A, with two large radio lobes, is an active galaxy.

Question 58

The astronomer who originally classified galaxies into S, E, and Irr was

A) William Herschel.
B) Edwin Hubble.
C) Henrietta Leavitt.
D) Harlow Shapley.
E) Carl Sagan.

Question 59

As the name quasi- stellar radio sources implies, all quasars are strong radio sources.

Question 60

Compared to our own Galaxy, elliptical galaxies

A) have bluer stars.
B) have no arms, but a better defined disk.
C) have more dust.
D) show more internal structure.
E) show no evidence of ongoing star formation.

Question 61

What are Type I supernovae used for?

A) explaining the pulsars in supernova remnants
B) standard candles for determining distances to other galaxies
C) age- dating the massive stars in clusters where they blow up
D) calculating the density of the interstellar medium from their remnants
E) determining the half- lives of the heavy elements they create

Question 62

Why does the Cepheid distance method fail us beyond about 20 Mpc?

A) The intergalactic dust reddens the Cepheid's light and apparent brightness.
B) Distant galaxies are seen in the past, and Cepheids evolve with time.
C) The periods of Cepheids grows longer as the distances increase.
D) Distant galaxies are younger than our Milky Way; too young to have Cepheids yet.
E) Even with the HST, the most luminous Cepheids are too faint to be seen beyond 20 Mpc.

Question 63

Which type of galaxy has a stellar disk, but without gas and dust?

A) E0
B) S0
C) E7
D) Irr I
E) SE

Question 64

You observe a spiral galaxy with a large central bulge and tightly wrapped arms. It would be classified a(n)

A) S0.
B) Sb.
C) Sc.
D) E7.
E) Sa.

Question 65

The Tully- Fisher relation exists between the galaxy's luminosity and its

A) size.
B) rotation.
C) age.
D) color.
E) mass.

Question 66

For finding the distance to M31, Hubble relied upon

A) Cepheid variables in its spiral arms.
B) planetary nebulae near its core.
C) RR Lyrae stars in its globular clusters.
D) Type I supernova in its core.
E) Type II supernova in its spiral arms.

Question 67

Which of these would be made up of only Population II stars?

A) Irr type II
B) Seyfert spirals
C) Irr type I
D) elliptical galaxies
E) barred spirals

Question 68

The greatest variation in size, mass, and luminosity occurs in

A) spiral and barred spiral galaxies.
B) elliptical galaxies.
C) Irr I vs. Irr II galaxies.
D) Seyfert galaxies.
E) globular clusters.

Question 69

What is the nearest huge cluster of thousands of galaxies, to which the Local Group may belong?

A) The Great Wall
B) Sagittarius Cluster
C) Virgo Cluster
D) Coma Cluster
E) Corona Borealis Cluster

Question 70

Within the boundaries of the constellations Coma and Virgo are found

A) the Large and Small Magellanic Clouds.
B) the closest red dwarfs to the Sun.
C) all the galaxies in the Local Group.
D) the largest nearby superclusters of galaxies.
E) the most distant known quasars.

Question 71

What is true of giant and dwarf elliptical galaxies?

A) The dwarfs contain more total mass than the giants.
B) The giants contain more total mass than the dwarfs.
C) There are more giants than dwarfs.
D) The giants are mostly blue, the dwarfs are mostly red.
E) They contain more dust than spirals.

Question 72

The flattest of all galaxies belong to class

A) Sc.
B) Irr II.
C) S0.
D) SBb.
E) E7.

Question 73

Which statement about the Magellanic Clouds is false?

A) They are companions of the Milky Way.
B) They are both irregular galaxies.
C) They contain regions of rapid star formation.
D) They are close to the south pole of the sky.
E) They are the two closest galaxies to us.

Question 74

In shape and component stars, elliptical galaxies are most like our own

A) companions, the Magellanic Clouds.
B) spiral arms.
C) halo.
D) galactic center.
E) nuclear bulge.

Question 75

What is true of the Local Group?

A) The Andromeda galaxy is a satellite of the Milky Way.
B) The giant ellipticals are the largest members.
C) It contains about 2500 galaxies.
D) The Andromeda galaxy (M31), and the Milky Way are the two largest galaxies.
E) It consists of mostly spirals.

Question 76

Most of the galaxies in the Local Group are

A) small irregulars like the Magellanic Clouds.
B) active galaxies like Centaurus A.
C) small spirals like M33 and the LMC.
D) small ellipticals like the companions to M31 in Andromeda.
E) big spirals like our Galaxy and M31.

Question 77

The Milky Way is considered to be an intermediately wound, barred spiral, which would be type , according to Hubble.

A) B2S
B) SBV
C) Sa
D) SBb
E) E4

Question 78

Which of the following is NOT one of Hubble's types of galaxies?

A) Seyfert spirals
B) dwarf ellipticals
C) barrel spirals
D) normal spirals
E) irregular type II

Question 79

A galaxy with little cool gas or dust and no evidence of ongoing star formation is most likely a(n)

A) barred spiral.
B) elliptical.
C) irregular.
D) spiral.
E) Seyfert.

Question 80

About how many galaxies are presently known in our Local Group?

A) 3
B) 27
C) 55
D) 107
E) 254