Deck 14: Galaxies

Question 1

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

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

Answer 1

E0.

Question 2

The Milky Way Galaxy's galaxy type is SBb.

Answer 2

True

Question 3

Collisions between galaxies have little effect on the individual stars.

Answer 3

True

Question 4

The smallest dwarf irregular galaxies are no richer in stars than the largest known globular clusters.

Question 5

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

A) Seyfert.
B) Spiral.
C) Barred spiral.
D) Elliptical.
E) Irregular.

Question 6

Some lobes of radio galaxies are in fact moving faster than the speed of light.

Question 7

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

Question 8

Gravity lensing lets us map the distribution of both visible and dark matter.

Question 9

Type I supernovae can be used to determine distances to galaxies much better than type II supernovae.

Question 10

The expansion of the universe means that stars in our Milky Way Galaxy are getting increasingly farther apart.

Question 11

It is now believed the majority of mass for most galaxies lies in their dark halos.

Question 12

For nearby spirals, their rotation curves help measure both light and dark matter.

Question 13

There is very little interstellar gas or dust in most elliptical galaxies.

Question 14

Galaxies are classified into types solely on the basis of their color.

Question 15

The flattest of the elliptical galaxies are class

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

Question 16

Astronomers observe unobscured X-rays generated in active galactic nuclei.

Question 17

Most galaxies are members of some sort of cluster of galaxies.

Question 18

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

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

Question 19

Active galactic nuclei are usually powered by supermassive black holes.

Question 20

The Milky Way's companion galaxies, the Magellanic Clouds, are irregular galaxies.

Question 21

According to Hubble's Law, the greater a galaxy's redshift, the

A) closer it is to us.
B) younger it is.
C) faster it's approaching us.
D) farther it is from us.
E) greater its mass.

Question 22

What is TRUE of spiral galaxies?

A) They are much less common at larger redshifts.
B) They are relatively rare in regions of high galaxy density.
C) They are only found in the center of rich galaxy clusters.
D) They have never been seen to have large redshifts.
E) They evolve from giant ellipticals.

Question 23

According to Hubble's Law, a galaxy with a velocity of 25,000 km/s will be

A) 100 million pcs away.
B) 400 million pcs away.
C) 700 million pcs away.
D) 1000 million pcs away.
E) less than 1 million pcs away.

Question 24

Which of the following paraphrases Hubble's Law?

A) The faster the galaxy spins, the more massive and luminous it is.
B) The greater the distance to a galaxy, the greater its redshift.
C) The greater the distance to a galaxy, the fainter it is.
D) The more distant a galaxy is, the younger it appears.
E) The older the galaxy appears to us, the more luminous it is.

Question 25

In Hubble's classification, which type of galaxy has no stellar disk and no gas or dust?

A) E0
B) S0
C) Sa
D) SBc
E) E9

Question 26

Quasar's spectral lines are

A) emission lines with large red shifts.
B) a continuum from the synchrotron radiation.
C) fuzzy absorption lines from the merged light of the billions of stars.
D) too complex for any interpretation.
E) nonexistent, the gas so hot as to be totally ionized, so no lines are seen.

Question 27

Most galaxies in the Local Group are

A) dwarf spirals.
B) small irregulars similar to the Magellanic Clouds.
C) larger spirals than either the Milky Way or M-31 in Andromeda.
D) dwarf ellipticals, similar to the companions of M-31.
E) brown dwarfs, with even more dust than our own Galaxy.

Question 28

What is TRUE of spiral galaxies?

A) They are much less common at larger redshifts.
B) They are relatively rare in regions of high galaxy density.
C) They are only found in the center of rich galaxy clusters.
D) They have never been seen to have large redshifts.
E) They evolve from giant ellipticals.

Question 29

The Large and Small Magellanic Clouds fall into class

A) SBc.
B) Pec.
C) E6.
D) Irr I.
E) E3.

Question 30

Which type of galaxy has a small bulge and loose, widely spread, poorly defined spiral pattern?

A) SO
B) S9
C) Sa
D) Sc
E) SBw

Question 31

Collisions between galaxies

A) are much rarer than collisions between stars.
B) can turn elliptical galaxies into spirals.
C) cause large numbers of stars to collide and explode.
D) cause the gas and dust clouds to collide, leading to rapid star formation.
E) are the best explanation for gamma-ray burst events.

Question 32

Why does the Cepheid "standard candle" have limited usefulness beyond 100 Mpc?

A) Distant galaxies are seen in the past, when Cepheid variables behaved differently than they do today.
B) Distant galaxies are so young they do not contain Cepheids.
C) Cepheids are too faint to be seen beyond that distance, even with HST.
D) The light variability of Cepheids diminishes with distance so they do not appear to vary there.
E) Older distant Cepheids are of population II, where the period-luminosity relation no longer works.

Question 33

While examining the spectrum of a galaxy you find all the hydrogen lines are shifted to longer wavelengths. This galaxy is

A) moving away from us.
B) moving towards us.
C) expanding explosively.
D) blue shifted.
E) not forming new stars.

Question 34

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

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

Question 35

Which of the following is NOT one of the normal types of galaxies?

A) Normal spirals
B) Barrel spirals
C) Seyfert spirals
D) Irregular type II
E) Dwarf ellipticals

Question 36

Quasars usually have their distances measured by what technique?

A) Type II supernovae
B) Cepheids
C) Parallax
D) Hubble's Law
E) Tully-Fisher relation

Question 37

That quasars were at cosmological distances yet appeared like ordinary faint stars meant

A) they were the brightest stars ever observed.
B) they must be very large.
C) they must contain many O and B type stars.
D) they must be producing such large quantities of energy than even fusion could not explain their output.
E) they must be very small, but bright due to gravitational lensing.

Question 38

Which statement about the Local Group is FALSE?

A) It contains about 45 member galaxies.
B) Its notable spirals include the Milky Way, M31, and M33.
C) Most of its members are dwarf elliptical and irregular galaxies.
D) It contains the large radio galaxy Centaurus A.
E) It is about three million light-years across.

Question 39

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

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

Question 40

An intermediately wound barred spiral galaxy would be

A) BS2.
B) BSE.5.
C) SBb.
D) S2B.
E) SIrr.

Question 41

Astronomers believe that a spiral galaxy may form

A) from a collision between a small and large galaxy.
B) due to a quasar shutting down.
C) from the sudden contraction of an elliptical galaxy.
D) from the collision of two giant elliptical galaxies.
E) from the explosion of a dwarf irregular galaxy.

Question 42

The magnetic fields carried by jets coming from active galactic nuclei are generated by

A) the combined magnetic fields of the many stars near the galaxy's center.
B) the central black hole.
C) the movement of the interstellar matter of the galaxy.
D) the movement of the stars in the galaxy.
E) charged matter in the accretion disk of the central black hole.

Question 43

The Magellanic Clouds are good examples of the ________ type of galaxy.

Question 44

According to their rotation curves, most spiral galaxies

A) rotate as a solid body.
B) rotate counterclockwise.
C) have decreasing rotational speeds with increasing distance.
D) contain dark matter.
E) contain dark energy.

Question 45

Collisions between galaxies is thought to

A) have stopped about 5 billion years ago.
B) be commonplace.
C) have never occurred.
D) be extremely rare.
E) have only occurred between 10 and 15 billion years ago.

Question 46

A galaxy that was once a quasar is likely to

A) have burned all its fuel by now and be dark.
B) now be a dwarf irregular.
C) have a black hole at its nucleus.
D) still be a quasar.
E) be less than 5 billion years old.

Question 47

Our galaxy, the Andromeda Galaxy, and about 40 smaller galaxies are members of ________.

Question 48

The pregalactic blobs had masses similar to

A) the earth.
B) the Sun.
C) globular clusters.
D) the Large Magellanic Cloud.
E) the Milky Way.

Question 49

In what sense are the quasars "quasi-stellar"?

A) Their energy production is hydrogen-helium fusion, like main sequence stars.
B) They are upscale versions of O stars, yet hundreds of times more massive.
C) Their luminosity comes from the millions of supergiants that compose them.
D) Their spectra is like that of ordinary stars.
E) In short time exposures, their images looked stellar.

Question 50

Rotation curves for spiral galaxies show

A) they are slowing down.
B) rotation speed drops off further from the nucleus.
C) most have dark halos.
D) most of the mass lies in the nucleus.
E) no relation to mass.

Question 51

In active galaxies, their central engines may be temporarily fed by

A) a sudden surge of star formation.
B) a series of supernovae around the core.
C) the sudden collapse of the core into a supermassive black hole.
D) a close encounter with a neighbor galaxy.
E) the fusion of helium into carbon in their cores.

Question 52

As we look at larger and larger scales in the universe, we find

A) smaller and smaller masses.
B) almost exclusively visible matter.
C) a larger and larger percentage of the matter is visible.
D) a larger and larger percentage of the matter is dark.
E) an equal amount of visible and dark matter.

Question 53

The lobes of a radio galaxy can be as much as

A) dozens of light-years from the galaxy's nucleus.
B) hundreds of light-years from the galaxy's nucleus.
C) thousands of light-years from the galaxy's nucleus.
D) millions of light-years from the galaxy's nucleus.
E) billions of light-years from the galaxy's nucleus.

Question 54

Although theory says a massive black hole with an accretion disk should be emitting X-rays, many black holes emit

A) mostly in the infrared.
B) only in the visible.
C) mainly in the gamma.
D) virtually no radiation at all.
E) equally across the entire electromagnetic spectrum.

Question 55

________ galaxies are essentially featureless; their light reveals evidence for the presence of only old red Main Sequence and red giant stars.

Question 56

The energy radiated by a typical quasar requires that its black hole accrete about

A) one solar mass a century.
B) one solar mass a decade.
C) one solar mass a year.
D) ten solar masses a year.
E) one solar mass a day.

Question 57

Based on galactic rotation curves and cluster dynamics, we think dark matter

A) is a minor component of the entire mass of the universe.
B) is best detected from the X-rays it produces in the intergalactic medium.
C) will have no effect on the fate of the universe.
D) comprises over 90% of the entire mass of the universe.
E) will doom the universe to collapse, overcoming the red shifts we now observe.

Question 58

Not only does the central engine of active galaxies and quasars require a black hole, but also ________ to provide the radiate energy.

A) globular clusters for food
B) a very strong magnetic field from neutron stars
C) a source of high-energy electrons for synchrotron radiation
D) an accretion disk of infalling matter
E) a high rate of rotation for the black hole

Question 59

In color photos, spirals typically have ________ arms with pink H II regions.

Question 60

Most active galactic nuclei are powered by

A) supermassive black holes.
B) a large number of supernovae.
C) mergers of compact objects.
D) black hole mergers.
E) extra-terrestrial civilizations.

Question 61

The ________ phenomenon is an extremely energetic event which apparently occurs in the nuclei of massive galaxies during an early stage of their evolution.

Question 62

Why would galaxies colliding in a small cluster tend to stick together, while galaxies in a large cluster tend to pass through each other?

Question 63

Giant elliptical galaxies may be the result of ________ in the centers of rich clusters.

Question 64

Distinguish an E0 from an E7 galaxy.

Question 65

Most galaxies are in ________, which contain hundreds or thousands of galaxies.

Question 66

Giant elliptical galaxies may be the result of ________ in the centers of rich clusters.

Question 67

Why is it that the quasars we see represent a time when the universe was younger?

Question 68

When two galaxies move very closely to each other, their ________ may dramatically rearrange their visible structures.

Question 69

What type of galaxy are the two Magellanic Clouds? How do we know this visually?

Question 70

The elliptical galaxies are most like what part of our Milky Way? Explain.

Question 71

To which portion of the Milky Way are the Magellanic Clouds most similar? Why?

Question 72

Distinguish an Sa from an Sc galaxy.

Question 73

Whether or NOT we see radio lobes from radio galaxies depends on their ________ relative to our line of sight.

Question 74

Hubble's Law starts as a plot of recessional ________ versus distance to the galaxies.

Question 75

Almost all active galactic nuclei seem to be involved in ________ with neighbors.

Question 76

What is a standard candle?

Question 77

The energy source for active galactic nuclei is probably a(n) ________ around a supermassive black hole.

Question 78

Why is Hubble's Law called the top of the distance ladder?

Question 79

Why do some radio galaxies appear to have lobes while some do not.

Question 80

From studies of the masses of individual galaxies and the masses of clusters of galaxies, it is now apparent that up to ________ of the universe is composed of dark matter.