1. Galaxies – Review Questions!

2. 16-1.The stars in which type of galaxy can be uniformly distributed in a sphere?
a) elliptical
b) normal spiral
c) barred spiral
d) irregular

3. 16-1.The stars in which type of galaxy can be uniformly distributed in a sphere?
a) elliptical *
b) normal spiral
c) barred spiral
d) irregular

4. 16-2. Which type of galaxy is presently the most commonly observed type?
a) normal spiral
b) barred spiral
c) elliptical
d) irregular

5. 16-2. Which type of galaxy is presently the most commonly observed type?
a) normal spiral
b) barred spiral
c) elliptical *
d) irregular

6. 16-3. The smallest known galaxies are of which kind?
a) elliptical
b) barred spiral
c) normal spiral
d) irregular

7. 16-3. The smallest known galaxies are of which kind?
a) elliptical *
b) barred spiral
c) normal spiral
d) irregular

8. 16-12. Which type of galaxy has very little gas or dust?
a) Elliptical
b) Spiral
c) Irregular
d) All of the above

9. 16-12. Which type of galaxy has very little gas or dust?
a) Elliptical
b) Spiral
c) Irregular
d) All of the above

10. 16-4. The largest known galaxies are of which kind?
a) elliptical
b) normal Spiral
c) barred Spiral
d) irregular

11. 16-4. The largest known galaxies are of which kind?
a) elliptical *
b) normal Spiral
c) barred Spiral
d) irregular

12. 16-5. If a galaxy is moving away from us, its absorption lines will:
a) change towards higher or lower wavelengths depending on the speed of the galaxy.
b) remain at the same wavelengths as lines from galaxies not moving away from us.
c) all change towards shorter wavelengths.
d) all change towards longer wavelengths.

13. 16-5. If a galaxy is moving away from us, its absorption lines will:
a) change towards higher or lower wavelengths depending on the speed of the galaxy.
b) remain at the same wavelengths as lines from galaxies not moving away from us.
c) all change towards shorter wavelengths.
d) all change towards longer wavelengths. *

14. 16-6. What is located between a disk galaxy’s spiral arms?
a) nothing
b) only interstellar gas and dust
c) almost as many stars as in the arms
d) more stars than are in the arms

15. 16-6. What is located between a disk galaxy’s spiral arms?
a) nothing
b) only interstellar gas and dust
c) almost as many stars as in the arms
d) more stars than are in the arms

16. 16-7. Which observation correctly applies to galaxies in other superclusters?
a) they are all moving towards us
b) they are all moving away from us
c) they are all larger than the Milky Way
d) they are all smaller than the Milky Way

17. 16-7. Which observation correctly applies to galaxies in other superclusters?
a) they are all moving towards us
b) they are all moving away from us *
c) they are all larger than the Milky Way
d) they are all smaller than the Milky Way

18. 16-8. Spiral density waves describe which of the following?
a) the ripples seen in comet tails
b) the pulses of a pulsar
c) the belts and zones in Jupiter’s upper layers
d) ripples in the gas of our Galaxy

19. 16-8. Spiral density waves describe which of the following?
a) the ripples seen in comet tails
b) the pulses of a pulsar
c) the belts and zones in Jupiter’s upper layers
d) ripples in the gas of our Galaxy *

20. 16-9. The Andromeda galaxy, in our local cluster, is
a) a spiral galaxy smaller than the Milky Way.
b) a spiral galaxy larger than the Milky Way.
c) an elliptical galaxy smaller than the Milky Way.
d) an elliptical galaxy larger than the Milky Way.

21. 16-9. The Andromeda galaxy, in our local cluster, is
a) a spiral galaxy smaller than the Milky Way.
b) a spiral galaxy larger than the Milky Way.
c) an elliptical galaxy smaller than the Milky Way.
d) an elliptical galaxy larger than the Milky Way.

22. a) measuring the distance to it using Cepheid variables.
Edwin Hubble first showed that Andromeda was a distant galaxy by
a) measuring the distance to it using Cepheid variables.
b) measuring the distance to it using RR Lyrae variables.
c) precisely measuring its parallax angle.
d) observing nova in the galaxy.

23. a) measuring the distance to it using Cepheid variables. *
Edwin Hubble first showed that Andromeda was a distant galaxy by
a) measuring the distance to it using Cepheid variables. *
b) measuring the distance to it using RR Lyrae variables.
c) precisely measuring its parallax angle.
d) observing nova in the galaxy.

24. Chapter 16 Thought/Writing Questions
1. List three methods of determining distances in the universe.
2. Why do spiral galaxies have spiral arms?

25. a) they have the highest blue shifts of any objects in the universe
17-1. Some quasars are among the most distant objects in the known universe. Which of the following statements about them must be correct?
a) they have the highest blue shifts of any objects in the universe
b) they have the smallest blue shifts of any objects in the universe
c) they have the highest red shifts of any objects in the universe
d) they have the smallest red shifts of any objects in the universe

26. a) they have the highest blue shifts of any objects in the universe
17-1. Some quasars are among the most distant objects in the known universe. Which of the following statements about them must be correct?
a) they have the highest blue shifts of any objects in the universe
b) they have the smallest blue shifts of any objects in the universe
c) they have the highest red shifts of any objects in the universe *
d) they have the smallest red shifts of any objects in the universe

27. The time for a fluctuation in brightness of a quasar allows astronomers to place an upper limit on its
a) luminosity.
b) size.
c) age.
d) distance.

28. The time for a fluctuation in brightness of a quasar allows astronomers to place an upper limit on its
a) luminosity.
b) size.
c) age.
d) distance.