Multiple-Choice Questions
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.
Page Ref: 15.1
2) The flattest of the ellipticals are class
A) E0.
B) SBO.
C) E7.
D) E9.
E) SBF.
Page Ref: 15.1
3) Which property is common to spiral galaxies?
A) On-going star formation and emission nebula in the arms
B) On-going star formation and emission nebula in the halo.
C) Globular clusters in the nucleus.
D) Open clusters in the halo.
E) Very little internal structure.
Page Ref: 15.1
4) The astronomer who originally classified galaxies into S, E, and Irr was
A) William Herschel.
B) Harlow Shapley.
C) Henrietta Leavitt.
D) Edwin Hubble.
E) Carl Sagan.
Page Ref: 15.1
6) Compared to our own Galaxy, elliptical galaxies
A) show more internal structure.
B) have bluer stars.
C) have more dust.
D) have no arms, but a better defined disk.
E) show no evidence of ongoing star formation.
Page Ref: 15.1
7) The Milky Way is often considered to be an intermediately wound, barred spiral, which would be type ________ according to Hubble.
A) E4
B) Sa
C) SBb
D) SBV
E) B2S
Page Ref: 15.1
8) The flattest of all galaxies belong to class
A) S0.
B) E7.
C) SBb.
D) Sc.
E) Irr II.
Page Ref: 15.1
9) In shape and component stars, elliptical galaxies are most like our own
A) galactic center.
B) spiral arms.
C) nuclear bulge.
D) halo.
E) companions, the Magellanic Clouds.
Page Ref: 15.1
10) What is true of giant and dwarf elliptical galaxies?
A) There are more giants than dwarfs.
B) The dwarfs contain more total mass than the giants.
C) The giants contain more total mass than the dwarfs.
D) They contain more dust than spirals.
E) The giants are mostly blue, the dwarfs are mostly red.
Page Ref: 15.1
11) Which type of galaxy has a stellar disk, but without gas and dust?
A) E0
B) E7
C) Irr I
D) S0
E) SE
Page Ref: 15.1
12) 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.
Page Ref: 15.1
13) A galaxy with little cool gas or dust and no evidence of ongoing star formation is most likely a(n)
A) elliptical.
B) spiral.
C) barred spiral.
D) irregular.
E) Seyfert.
Page Ref: 15.1
14) Which of the following is not one of Hubble's types of galaxies?
A) Normal spirals.
B) Barrel spirals.
C) Seyfert spirals.
D) Irregular type II.
E) Dwarf ellipticals.
Page Ref: 15.1,15.4
15) 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
Page Ref: 15.1
16) Which of these would be made up of only population II stars?
A) galaxies
B) Irr type I
C) Irr type II
D) barred spirals
E) Seyfert spirals
Page Ref: 15.1, 15.4
17) 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 consists of mostly spirals.
D) The Andromeda galaxy (M31), and the Milky Way are the two largest galaxies.
E) It contains about 2500 galaxies.
Page Ref: 15.2
18) Within the boundaries of the constellations Coma and Virgo are found
A) all the galaxies in the Local Group.
B) the most distant known quasars.
C) the largest nearby superclusters of galaxies.
D) the closest red dwarfs to the Sun.
E) the Large and Small Magellanic Clouds.
Page Ref: 15.2
19) About how many galaxies are presently known in our Local Group?
A) 3
B) 27
C) 45
D) 107
E) 254
Page Ref: 15.2
20) Why does the Cepheid distance method fail us beyond about 20 Mpc?
A) Distant galaxies are seen in the past, and Cepheids evolve with time.
B) Distant galaxies are younger than our Milky Way; too young to have Cepheids yet.
C) The intergalactic dust reddens the Cepheid's light and apparent brightness.
D) Even with the HST, the most luminous Cepheids are too faint to be seen beyond.
E) The periods of Cepheids grows longer as the distances increase.
Page Ref: 15.2
21) What is the nearest huge cluster of galaxies to our Local Group?
A) Coma Cluster
B) Centaurus Cluster
C) Virgo Cluster
D) Orion Nebula
E) Hercules Cluster
Page Ref: 15.2
22) What are Type I supernovae used for?
A) Explaining the pulsars in supernova remnants.
B) Calculating the density of the interstellar medium from their remnants.
C) Age-dating the massive stars in clusters where they blow up.
D) Standard candles for determining distances to other galaxies.
E) Determining the half-lives of the heavy elements they create.
Page Ref: 15.2
23) Which statement about the Magellanic Clouds is false?
A) They are both irregular galaxies.
B) They are companions of the Milky Way.
C) They contain regions of rapid star formation.
D) They are the two closest galaxies to us.
E) They are close to the south pole of the sky.
Page Ref: 15.2
24) Most of the galaxies in the Local Group are
A) big spirals like our Galaxy and M31.
B) small spirals like M33 and the LMC.
C) small irregulars like the Magellanic Clouds.
D) active galaxies like Centaurus A.
E) small ellipticals like the companions to M31 in Andromeda.
Page Ref: 15.2
25) For finding the distance to M31, Hubble relied upon
A) RR Lyrae stars in its globular clusters.
B) Type I supernova in its core.
C) Type II supernova in its spiral arms.
D) Cepheid variables in its spiral arms.
E) planetary nebulae near its core.
Page Ref: 15.2
26) The Tully-Fisher relation exists between the galaxy's luminosity and its
A) color.
B) age.
C) rotation.
D) mass.
E) size.
Page Ref: 15.2
27) 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.
Page Ref: 15.2
29) 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.
Page Ref: 15.3
30) 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.
Page Ref: 15.3
31) The nearest lobe radio galaxy to our Milky Way is
A) the Whirlpool, M51.
B) Centaurus A.
C) M13 in Hercules.
D) M42 in Orion.
E) M87 in Virgo.
Page Ref: 15.4
32) 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.
Page Ref: 15.4
33) Why is the energy source for active nuclei like Seyferts thought to be compact?
A) The sources appear to be single stars in photos.
B) Their energy appears to be non-stellar synchrotron radiation.
C) The light can vary over short time intervals.
D) We know the masses of the black holes that lurk there, and can find their radii.
E) They are all strong radio sources, with assigned frequencies by their sizes.
Page Ref: 15.4
34) The key to finding quasar's distances was Marteen Schmidt's finding
A) a Type I supernova in the spiral arm of 3C87.
B) the huge red shifts of the hydrogen lines in 3C273.
C) planetary nebula in M51.
D) the luminosity of 3C52 from the Doppler shift and the Fisher-Tully relation.
E) globular clusters in the halo of M87 in Virgo.
Page Ref: 15.4
35) What is true of the lobes of a radio galaxy?
A) They are perpendicular to the galactic plane.
B) They are hotter than the galactic core.
C) They radiate primarily in the x-ray.
D) They extend out along the galactic plane.
E) They form close to the edge of the galaxy.
Page Ref: 15.4
36) 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.
Page Ref: 15.4
37) In the gap between quasars and normal spirals lie
A) lobe radio galaxies.
B) Irr II galaxies.
C) S0 galaxies.
D) Seyfert galaxies.
E) Fisher-Tully galaxies.
Page Ref: 15.4
38) A billion solar mass black hole would still have a radius of only
A) 20 AU.
B) 15 parsecs.
C) 150 kilometers.
D) 3 kpc.
E) two million light years.
Page Ref: 15.5
39) Synchrotron radiation produces a ________ spectrum.
A) continuous nonthermal
B) emission line
C) absorption line
D) continuous, with some emission lines
E) continuous, with some absorption lines
Page Ref: 15.4
40) 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.
Page Ref: 15.5
41) 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.
Page Ref: 15.5
42) 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
Page Ref: 15.5
43) What percentage of the accreted mass into a black hole can be radiated back out?
A) .007
B) 8%
C) 20%
D) 50%
E) 99.9%
Page Ref: 15.5